Reporting tonight, lester holt. Good evening. As we start tonight were watching several big stories including the search for wreckage and survivors of the scene of a deadly military Helicopter Crash overnight off the coast of florida. We want to begin here this evening with what appears to be another embarrassment for the secret service. Details just surfacing about an investigation into a possible car crash on the white house grounds involving members of the secret service including an agent assigned to president obamas protective detail. Lets go right to nbcs tom costello in our washington newsroom. Tom . Reporter lester, good evening. A Senior Administration official is confirming to nbc news this evening that there is an investigation into the actions of two secret Service Agents including a top member of the president s protective detail. The secret service confirming its looking into what happened on march 4th when two agents drove a government vehicle into a White House Security perimeter. The agents had been working at a party for a retiring spokesperson. They conducted sobriety tests but were told by a supervisor to let the agents go home. At the time of the incident the officers at the white house were investigating a suspicious package on white house grounds. The agents arrived using their emergency flashing lights, which may have been a violation of secret service regulations. Government officials tell nbc news the secret service is now working with the Homeland SecurityInspector General to conduct an investigation. We have learned two employees have now been reassigned. All of this coming after the former head of the secret service was forced out following a series of highprofile scandals at the agency. Lester . All right, tom costello tonight, thank you. Now to the other big story were following here. The families of 11 American Service members are receiving the worst possible news following a deadly training accident off the gulf coast of florida. The military says four Army Aviators along with seven marines were aboard a black hawk helicopter that crashed during a nighttime near Eglin Air Force base. No survivors have been recovered, making this among the deadliest military training accidents in years. Mark potter is near the crash site. Reporter searchers spent the day looking for debris from the Army Black Hawk helicopter which crashed overnight off the florida panhandle. Washed up on shore, a piece of landing gear with a medical kit nearby and what appears to be a window from the downed aircraft. Searchers also recovered most of the human remains in the dense fog. As you know, the fog has been hampering those operations throughout the morning and day. Reporter Officials Say the crash occurred early last night in the santa rosa sound. They lost track of the chopper around 8 30 p. M. Erica stone lives along the sound and believes she heard the crash somewhere out in the fog. We heard a loud sound. You know, kind of like a bombing but a little different. Reporter her husband, jasper, awoke this morning to find pieces of the chopper and jet fuel coming ashore on his property. Every four or five feet or so there was some beach ball size debris. Reporter on board the chopper were seven u. S. Marines and four Army National guard crew members on a nighttime training mission. I can tell you they had several thousand hours in that cockpit and they had several thousand combat hours in that cockpit. Reporter a pentagon official says its feared all perished. The black hawk uh60 is the workhorse of the u. S. Military. It can carry up to 14 troops at a time with a crew of four. It has a range of 370 miles with a top speed of 170 miles an hour. The marines aboard were from camp lejeune north carolina. The helicopter battalion based in hammond, louisiana, had never lost a soldier until now. In iraq it flew Saddam Hussein after capture in 2006. And after Hurricane Katrina helped rescue thousands, plucking many off rooftops. And witnesses say the dense fog that were seeing now is not nearly as bad as it was at the time of the crash. Meantime, officials have not yet suggested why that crash occurred. Lester . Mark potter covering that story tonight. Thank you. Now to a development that protesters have been calling for practically ever since a Police Officer shot Michael Brown dead in ferguson, missouri. The city and the police chief, thomas jackson, have agreed to what theyre calling a mutual separation. That means the chief is stepping down effective next week. Nbcs ron allen with this report. Reporter Ferguson Police chief tom jackson has faced withering criticism since the death of Michael Brown last august. His decision to withhold officer wilsons name while releasing video of brown in a robbery, fueled calls for resignation. The Justice Department investigation found jackson was running a Police Department rampant with racial bias. More focused on raising revenue through the courts than public safety. He had resisted constant calls to step down. Jackson city manager john shaw out the door. We expect you to do more. Reporter the Council Approved a mutual separation agreement last night. And the top judge who resigned after Missouri Supreme Court ordered a higher ranking judge to take over. Before that the city fired its top clerk and two Police Supervisors resigned after the doj report linked them to racially charged emails. The fallout may continue as federal investigators press for reforms theyve said dismantling the Police Department is not out of the question. In a statement to nbc news, jackson said hes confident the city will pull through these trying times. The Ferguson Police supervisor will now take over while the city conducts a nationwide search for a new police chief. Lester . Ron allen, thank you. National leaders for the Fraternity Chapter caught on video singing racial slurs say that the chant is not part of the fabric of their organization. But there are questions tonight about whether the song or at least the sentiment in it has been heard in chapters beyond the one at the university of oklahoma. Nbcs Gabe Gutierrez has been looking into it. [ bleep ]. Reporter Sigma Alpha Epsilon today said racist behavior entered its university of Oklahoma Chapter three to four years ago calling it a horrible cancer. We had to cut that cancer before it infects too many other groups. Reporter saes National Spokesman says the fraternity has so far been unable to verify reports of similar chants at other campuses. Parker rice, one of the sae members in this video, said the song was taught to us. When somebody says it was taught to us, we know it was not the national headquarters. It wasnt even something that would be part of our history at all. Reporter rice said i am deeply sorry for what i did saturday night. It was wrong and reckless. I admit it likely was fueled by alcohol consumed at the house before the bus trip. But thats not an excuse. The parents of a second Fraternity Member in the video, levi pettit also apologized, he made a horrible mistake and will live with the consequences forever. Its an old fraternity tradition of singing these types of songs. Reporter andrew who in college was in sae and now is an outspoken critic of greek life. Racism is alive and well in american campus especially fraternities. Reporter active member of the university of Cincinnati BlackStudent Association and proud sae member. We do not act like that. That bad behavior is not something that we represent. Reporter in 2013 the sae chapter at Washington University in st. Louis was suspended following allegations that pledges sang racial slurs to africanamerican students. Last year, clemson universitys chapter was suspended for holding a racially themed party. Now at ou the growing scandal has sparked a rallying cry. And today the normally silent statues spoke volumes. All the members have moved out of the sae house here on campus. And now the National Organization is looking to kick them out permanently. Lester . All right, gabe, thank you. New developments to report tonight in the controversy over Hillary Clintons use of a private email account for government business. The state departments watchdog said today that many emails by mrs. Clinton and other officials may not have been saved automatically as clinton claimed. Nbcs Andrea Mitchell has been looking into it. Reporter defending her use of private emails, Hillary Clinton said her emails to her state Department Colleagues were saved by them. It was my practice to communicate with state department and other government officials on their dotgov accounts. So those emails would be automatically saved in the state Department System to meet recordkeeping requirements. And that indeed is what happened. Reporter but only 24 hours later a new state department Inspector Generals report says for the past five years most important state Department Emails for all of the state department were not properly archived. The report says a computer upgrade in 2009 when clinton took office failed to preserve thousands of key policy emails. For example, in 2011, employees archived only 61,156 emails out of more than 1 billion sent. Why . Inspectors found employees did not receive adequate training. The Computer System kept breaking down. And some employees deliberately avoided creating computerized records that could be searched later. The state Department Just wasnt saving its emails. Not mrs. Clintons, not all the people responsible for our foreign policy. Reporter clinton is also being challenged for her claim she never sent a classified email. I did not email any classified material to anyone on my email. There is no classified material. Reporter republicans were skeptical. And even the white house didnt rush to her defense. Ultimately i think it will be up to all of you to make your own determinations about sort of how secretary clinton has resolved this matter. Reporter clinton stumbled over how shes handled this controversy have in fact persuaded advisers she needs to speed up her Campaign Launch now likely in just a few weeks. Lester . Just to be clear, this report a coincidence, the timing. Totally. Theyve been investigating for three years. Andrea mitchell, thank you. Heated moments in the Nations Capital when officials from the Obama Administration came facetoface with republicans who signed a letter warning iran that any nuclear deal that it could strike with the u. S. May not be worth the paper its printed on. More from nbcs peter alexander. Reporter with the white house and Congressional Republicans clashing over a nuclear deal with iran, today a direct confrontation on capitol hill. Secretary of state john kerry blasting the letter sent by Senate Republicans to irans leaders this week. In my reaction to the letter was utter disbelief. Reporter that letter warns one of americas enemies that any Nuclear Deal Reached with the president and u. S. Allies could be undone if it isnt approved by congress. Kerry called it irresponsible and misleading. It purports to tell the world if you want to have any confidence in your dealings with america, they have to negotiate with 535 members of congress. That is both untrue and profoundly a bad suggestion to make, i think. Secretary, i know thats a wellwritten speech not a speech, my friend. This is not a speech. This indignation and breast beating over this letter is absolute nonsense. Reporter this morning on today, rand paul who signed the letter insisted it doesnt undermine the president. Were going to have to get this agreement by congress and in doing so maybe the president will negotiate a more appropriate deal. Reporter Hillary Clinton took aim at potential republican opponents in 2016, like rand paul, tweeting, no one considering running for commander in chief should be signing on. Tonight, more than 170,000 people have petitioned the administration to file charges against those 47 republican senators for violating whats called the logan act that forbids citizens from negotiating disputes between the u. S. And a foreign government. With that many petitioners by its own rules, the white house will have to respond. Lester . Peter alexander at the white house, thank you. Now to a war that continues to create some unlikely alliances. Iran is now playing what could turn out to be a decisive role in the fight against isis in iraq. The battle to win back a major city from isis militants. Its the biggest counteroffensive against isis so far. Nbcs bill neely with more tonight from northern iraq. Reporter its a decisive moment. Iraqi fighters surrounding tikrit trying to drive isis out of a major city for the first time. Theyve begun slowly to push into the city that gave birth to iraqs former dictator Saddam Hussein. But outnumbering the flags of iraqs army are those of shiite militias, a rainbow thats alarming the u. S. Because these are men armed, trained and backed by iran. Directing them from tikrit is the head of the Iranian Revolutionary guards elite force. Americas top general told Congress Today that of the 24,000 men attacking tikrit, 20,000 are iranianbacked. The activities of the iranians to support for the Iraqis Security forces is a positive thing in military terms against isil. But we are all concerned about what happens after the drums stop beating and isil is defeated. Reporter but the u. S. Is an onlooker watching irans men from the sidelines, no air strikes here, no help. The u. S. Believes tikrit will fall. And fears the iranianbacked shiite militias could go on the rampage against its sunni population. Isis may lose tikrit, iran intends to win the bigger battle for iraq. And that would be no gain at all for the u. S. Bill neely nbc news erbil, iraq. Theres a lot more to tell you about here tonight including a booster shot that may have helped this cancer patient live to see her grandchildren. Its fascinating. Also news about that baby who survived a terrible car crash and waters of a frigid river. Well be back. A Promising Development to report tonight in battling one of the hardest forms of cancer to treat. Nearly 23,000 americans are diagnosed with brain cancer each year. Now researchers have found that a simple tetanus shot might boost the chances of some Patients Living years longer than they expected. Nbcs Stephanie Gosk explains. Reporter every day sandy walks and walks. Nine years ago, a doctor told her she had just two to three months to live. How many miles you walk every day . Nothing, just two to four. Reporter nothing just two to four. Thats a lot. Two to four . It just feels good. Reporter her diagnosis, gleoblastoma, brain cancer. Highly aggressive, its an absolutely devastating disease. And universally fatal. Reporter but she took part in a Duke University medical trial that extended her life. So the grandmother of two can now proudly say she is a grandmother of six. The study was small, 12 people altogether. Following standard surgery, chemotherapy and radiation all received a novel therapy that uses the bodys own immune system. Six were also given a dose of a wellknown vaccine, the tetanus booster. If you give patient a boost of tetanus, it sort of puts the lymph nodes acting like a siren to the rest of the cells. Reporter so when immunotherapy is given, doctors believe the body is trying to fight the cancer cells more aggressively. The median survival rate for the six who received the tetanus shot was over six years, which is twice as long as the patients who received standard therapy. Hillburns success exceeded all expectations. And she still has no sign of a tumor. Doctors say its too early to know for sure but theyre hopeful the research can help fight other aggressive cancers as well. I have such a good quality of life. And i am grateful for the vaccine for that. Reporter Sandy Hillburn is the walking proof. Stephanie gosk, nbc news, new york. Were back in a moment with late word in an arrest in the attempted kidnapping caught on tape. This was the scene on i94 in michigan today between dearborn and detroit. A tanker truck carrying thousands of gallons of fuel exploded in a big fireball. No one was seriously injured, but the blast caused a daylong traffic headache in both directions. Now an update to a story we brought you last night about this brazen abduction attempt caught on tape. Police say theyve arrested a 15yearold suspect. But theyre not releasing a name due to his age. Hes accused of snatching a 22monthold from a park and then abandoning the victim after the toddler, siblings and others gave chase. And an update tonight on that baby girl who somehow survived after her mothers car crashed into a frigid utah river. 18monthold lily grossbeck was reunited with her family today and was released from the hospital four days after she was rescued from the overturned and partially submerged car. She remained upsidedown for almost 14 hours and was able to escape the water. Sadly, her mother did not survive. When we come back here tonight, why some folks are really happy about getting a ticket from the police. Finally tonight, for anyone who has suffered the aggravation of getting a ticket from the police, this ones for you. Harry smith found a police force in New Hampshire on the lookout for good behavior. Farmington police. Reporter when detective Brian Driscoll walks the beat, he keeps an eye out for the activity that often goes unnoticed. Let me you guys have been using every single crosswalk. Reporter yes, in farmington, New Hampshire, they give citations for good behavior. Heres a free gift card for pizza. Thank you. Reporter well, not citations really. But gift cards for a free slice of pizza or an order of fries. Wary citizens quickly warm to the idea. What did you think when the policeman was coming up to you . It was just like, okay, what did i do . Reporter the tactic was dreamed up by chief jay drury as he watched a man go out of his way to use the crosswalks during a snowstorm. I thought to myself, this gentleman deserves a medal. Reporter he brought the idea to a local convenience store. And they jumped onboard. Its given us a different perspective and now were out looking for good things. Reporter while farmington looks like a yankee version of mayberry, beneath this Norman Rockwell facade is a town hit hard by drugs and domestic violence. We end up seeing 10 of the people 90 of the time. Reporter so the gift cards help form connections and build community trust. I just wanted to thank you guys for doing the right thing and making my job a little bit easier. Well, thank you for doing this. This is a neat program. Youre the reason why we do it. Reporter an idea so simple it might just work. Harry smith, nbc news, farmington, New Hampshire. And that will do it for us on this wednesday night. Im lester holt. Thank you for joining us. For all of us at nbc news, good night. Right now at 6 00 ellen pao on the stand today. And her testimony giving critical details about what she says goes on inside one of the nations premier capital firms. Good evening, everyone. Thank you for joining us. Be careful what you write from your Company Email account. Today emails from years ago took center stage in the ellen pao criminal case. She was peppered by the lawyers. Mark mathews is joining us from the courthouse. Reporter ellen pao is undergoing a she is armed with emails and a taped deposition, and shes using them to great effect. Ellen pao testified she was pressured into a sexual relationship with a fellow partner and he tried to cut her out of meetings and emails after she broke off the email after discovering he had not separated from his wife. Today the attorney confronted pao with her own emails showing she did not want him punished for the affair. And when her boss said she didnt have to work with him