This is the cbs evening news with jeff glor. Glor this is our western edition, good evening. Well begin tonight with walkouts across the country as a suspect appears in court in florida. Hundreds of thousands of High School Students left schools for at least 17 minutes, one minute for each of the People Killed in parkland one month ago today. At the u. S. Capitol, students were joined by some house and senate leaders. The National Walkout was inspired by students of Marjory StonemanDouglas High School, and adriana diaz was there tonight. Reporter a sea of students streamed out of the school behind a national movement. Parents at Marjory StonemanDouglas High School cheered them on, like rick and rosemary jensen. This wasnt the way i wanted my son to become an activist, but, you know what, im so glad the kids have found their voices. Uoyinghope it is what is buoying them, because this isnt easy for them. Reporter freshman alexa palen and Brianna Jesionowski hugged by a memorial for their friend, 14yearold gina montalto. Does a walkout, like what you guys are doing, do you think it helps . It does help, because it shows that the community is so hrong and that we are coming through this together. Reporter but the father of 14yearold victim alaina petty wants a different approach. On twitter, ryan petty encouraged students to walk up to the kid who causes nts urbances in class and ask how hes doing, adding the hashtag walk up, not out. Still, in portland, oregon, orudents in florida left a clear message, and snow in akron, ohio, didnt stop the students from showing their support. This is what democracy looks like reporter in nearby chicago, nearly 1,000 students left Jones College prep, but they say the rest of america is now grappling with the gun violence theyve battled for years. Y they dont live in cities or communities where guns play constantly, where children are dying 24 7 in the streets, no matter if theyre coming to or from school. Reporter in washington, d. C. if you can speak, speak if you can march, march reporter young people wanted their voices heard. Kate whitman organized her School Walkout in new york city. We saw this in the 60s and the 70s with m. L. K. , with the vietnam protest, and were seeing this here right now. This is a part of history reporter while the walkout was underway, the n. R. A. Tweeted, lets Work Together and secure our schools and stop school violence. , protect our banks, our sports stadiums and our government buildings better than we protect our schools. The n. R. A. Wants congress to push through legislation that increases school safety. Jeff . Glor adriana diaz in parkland, thank you very much. Ere gunman in the School Shooting stayed silent today. His lawyers repeated their offer nikolas cruz will plead huilty if his life is spared. Prosecutors rejected it. Theyre going for the death penalty. Newly released 911 calls from inside the high school reveal a frantic effort to save the wounded before help arrived. Glor Coral Springs police say they fielded 115 calls in two hours after the shooting. At a high school in seaside, california, a lesson in gun safety yesterday did not go as planned. It ended with three students wounded. Ireya villarreal says this was not an isolated incident. Reporter as a california enacher attempted to instruct students about gun safety in his criminal justice class, the gun accidentally went off. Dennis alexander, a reserve officer, city councilman, and teacher, is now on administrative leave. My gosh, good that it went up to the ceiling. What if someone somehow got it . Reporter three students were hit by falling debris when the bullet hit the ceiling. Bu fragments from the bullet struck a student in the neck. Ay, eporter also on tuesday, a School Resource officer in iaexandria, virginia, accidentally discharged his weapon in his office. No one was hurt. Two weeks ago, a teacher in g lton, georgia was arrested after barricading himself inside a classroom and firing at the schools principal. Incidents like these come amid calls to arm teachers in schools nationwide. Education secretary betsy devos addressed it on 60 minutes. Do you think that teachers should have guns in the classroom . That should be an option for states and communities to consider. St reporter the president sideinues to suggest that teachers should be allowed to carry concealed weapons on campus. Le far, in at least 11 states, School Staff Members are allowed to carry weapons in school or have access to them. Jeff . Glor mireya, thank you. There is breaking news in the florida keys tonight. A Navy Fighter Jet crashed this evening near key west. We navy says it was an f18 hornet, like the one you see here on the screen. The twoperson crew based in norfolk, virginia, ejected ctfore the crash. They were recovered. Their condition, though, is not known, nor is the cause of that wreck. In vermont today, there was an avalanche as u. S. Soldiers were conducting advanced mountain training. Six of them were hurt. Rescuers raced up the mountain to free them. Osve were taken to the hospital. None of the injuries are considered lifethreatening. Anis was the second avalanche to hit that area in several days after heavy snowfall. At the white house tonight, the shakeup continues. A new economic adviser is about more tin, and more top members of the Administration May soon be leaving. Jericka duncan has the latest. And i have a great job. So youre not leaving . I am not leaving. Youre not leaving. applause louieporter the president was touting Economic Growth and job security in st. Louis today, but back at the white house, jobs seemed anything but secure. Cnbc television contributor larry kudlow was named director of the National Economic council, replacing gary cohn, who announced his departure last week. The greatest and most important thing for this or any other country is rapid Economic Growth and prosperity for everyone. Reporter so far, more than 20 Senior Administration staffers have either been fired, resigned, or reassigned. Good afternoon, all. Reporter just yesterday, the thesident pushed out secretary of state rex tillerson, and theres talk of more changes. Secretary of Veterans Affairs and obamaera holdover david an shulkin could be next to get the ot. T. In february, the Inspector General determined shulkin used fterayer dollars on a lavish trip to europe for his wife. He paid the money back after it became public. And National Security adviser h. R. Mcmasters departure has been expected for weeks. Sources say mcmaster and ve cident trump have clashed over policy, something the president said he relishes. I like conflict. I like having two people with different points of view, and i certainly have that. And then i make a decision. Reporter but trumps likely cmck to take mcmasters place is former u. S. Ambassador to the wn. , john bolton, whose Foreign Policy ideas are more closely aligned with the president s. Secretary of housing and urban Development Ben carson has also come under fire for spending 31,000 on a dining room set for his office. That order, jeff, was eventually canceled. Glor jericka, thank you. Cbs news has confirmed that e drew mccabe, once the Deputy Director of the f. B. I. , could be fired this week, just days short of his official retirement from the bureau. Jeff pegues is following this story. Jeff . Reporter jeff, as you know, Andrew Mccabe has been caught up ep a highlevel investigation by mccdepartment of justice Inspector General. That probe is about how the f. B. I. Conducted its investigation of Hillary Clintons private email server. The final report is due soon, but according to sources familiar with its conclusion, it says mccabe misled investigators about whether he had talked to a stporter about an f. B. I. Investigation into the clinton on,ndation. The f. B. I. Has recommended mccabe be fired, and now its up to the attorney general, jeff session, to decide. If mccabe is fired, he could lose his pension. Cacabe has been a frequent target of President Trump over the last year. In december, the president tweeted, f. B. I. Deputy director Andrew Mccabe is racing the clock to retire with full benefits. 90 days to go. Mccabe, by the way, also led the initial stages of the russia investigation. Within the f. B. I. , lying during an investigation is considered a cardinal sin. We did reach out to mccabe, but we have not yet heard back. Jeff . Glor all right, jeff. Thank you. Britain expelled 23 Russian Diplomats today after the poisoning of a former russian spy. Sergei skripal was attacked with a nerve agent developed by the soviet union. He and his daughter are in critical condition. The white house expressed solidarity with britain. At the u. N. Security council, dos. Ambassador nikki haley pointed the finger at russia. If we dont take immediate, concrete measures to address this now, salisbury will not be the last place we see chemical weapons used. They could be used here in new york or in cities of any country that sits on this council. Glor russian president Vladimir Putin said nothing about this today. He was busy campaigning for reelection in crimea, the province he took illegally from ukraine. Elizabeth palmer is there. Reporter this is putins warmup. And this is his base. Pumping up potential russian voters is the name of the game now. There is no question that ngesident putin is going to win the election on sunday. Its no contest. And for that reason, a lot of russian voters are apathetic. So the kremlin is working hard to make sure theyre not embarrassed by low turnout. Putins message today was proudly nationalistic. Crimea, he said, has returned home to russia. He is talking about 2014, when Russian Troops wearing uniforms with no insignia, the socalled little green men, seized crimea from ukraine. At the time, putin denied he sent in the military. And then, when it was all over, he bragged about it. The u. S. And most countries called the seizure illegal, d d slapped on sanctions. But today on his whirlwind tour, putin visited the bridge russia is building to physically link its mainland to crimea, a pogaproject thats wildly popular with russians who support the land grab. But its also a message to the west putin never backs down. Thats Something Else russian t ters love about him. As he said before he left the stage, i would like to hug you all. President putin made no mention of the growing rift with britain over the poisoning of the russian exile, sergei skripal. Act the very fact that he held his rally here in disputed territory makes a bold statement about russias attitude to international law. Jeff . Glor indeed it does. Liz palmer in crimea. Thank you. A new study out today finds icaln who are physically fit may be 90 less likely to develop dementia. Orth more on the link between a healthy body and a healthy mind, cbs news medical contributor dr. Tara narula is here now. Tara . Reporter hi, jeff, how are reu . Jeff good. Reporter so this is an interesting study. Researchers looked at about 190 swedish women who are middle aged. They gave them a fitness test and tried to tell whether they had low, medium, or high levels of fitness. They then followed them for neout 40 years to see who developed dementia. And they found that those in the highest fitness level group on average developed dementia at a erte of about 5 compared to f abouin the lowest, who developed it at the rate of aout 32 . In addition, higher levels of fitness seemed to delay the onset of dementia. So instead of getting dementia at the age of 79 in the medium fitness group, you would develop it at the age of 90, 11 years later, if you were at the highest level of fitness. Glor do we know why people working out develop this protection . Reporter its interesting, we dont know for sure. Some may be the indirect effects of controlling cardiovascular risk factors, blood pressure, cholesterol, diabetes, obesity, improving blood flow to the brain. However, there may be also a component directly affecting the brain, where youre improving the architecture, the wiring, the connectivity, and communication going on in the mmain itself. Glor so any of this physical fitness that you can squeeze in is obviously a very good thing. Reporter yes, and the earlier you start the better. You dont have to do crazy levels of fitness. 150 minutes a week of moderate level aerobic activity. Glor good to hear. Tara, thank you very much. Coming up next on the cbs evening news, when dogs fly. Onited airlines delivers the wrong dogs to the wrong cities. And, the mediocre student who captured the imagination of the world. Each day justin chooses to walk. At work. And after work. He does it all with dr. Scholls. Only dr. Scholls has massaging gel insoles that provide allday comfort. To keep him feeling more energized. Dr. Scholls. Born to move. How much money do you think youll need in retirement . Then we found out how many years that money would last them. How long do you think well keep oooooohhh you stopped youre gonna leave me back here at year 9 . How did this happen . It turned out, a lot of people fell short, of even the average length of retirement. We have to think about not when we expect to live to, but when we could live to. Lets plan for income that lasts all our years in retirement. Prudential. Bring your challenges. Copdso to breathe better,athe. I go with anoro. Go your own way copd tries to say, go this way. I say, ill go my own way with anoro. Go your own way oncedaily anoro contains two medicines called bronchodilators, that Work Together to significantly improve lung function all day and all night. Anoro is not for asthma. It contains a type of medicine that increases risk of death in people with asthma. The risk is unknown in copd. Anoro wont replace rescue inhalers for sudden symptoms and should not be used more than once a day. Tell your doctor if you have a heart condition, high blood pressure, glaucoma, prostate, bladder, or urinary problems. These may worsen with anoro. Call your doctor if you have worsened breathing, chest pain, mouth or tongue swelling, problems urinating, vision changes, or eye pain while taking anoro. Ask your doctor about anoro. Go your own way get your first prescription free at anoro. Com. As glor this is the point in tosterdays broadcast where we told you about the puppy that died on a united flight after it was forced to travel in the ad comad compartment. The f. A. A. Is looking into that. Now, another canine embarrassment for united. Here again is kris van cleave with a tale of two dogs sent the wrong way. Reporter tenyearold German Shepherd irgo was supposed to fly from oregon to kansas city. But when owner, carol swindle, arrived in kansas city, he was given a great dane instead. The dogs got switched, and irgo went to japan. At this point, all i can do is be hopeful that my dog is going to be okay and return safely. Reporter united says the error happened during the dogs connection in denver. Today, the airline is apologizing, something its done a lot this week. He was barking during the flight. That stopped, like, after two hours. Reporter monday night, on a flight from houston to new york, a Flight Attendant ordered them to put this bag in the overhead bin. Inside was their tenmonthold french bulldog, kokito. She was literally not moving or anything. Reporter kokito died. United admits the Flight Attendant did not hear or understand and did not knowingly place the dog in the overhead bin. More than 500,000 animals flew in 2017, nearly 140,000 on united. Overall, 24 died; 18 of those on united. What happened with this is disgraceful. Reporter republican senator john kennedy, himself a dog owner, plans to push legislation banning animals from the hierhead bin. We need to get to the bottom ba it. And i know we have many important things to do, but this is important too. Glor kris, what is united saying about this tonight . Reporter well, united said tarting in april, they are going to issue brightly colored tags for carryon bags that contain live animals. Thats to further flag flight crews that there is a live animal inside. Senator kennedy plans to submit his bill tomorrow. And as for irgo, his japanese adventure is going to last a little bit longer. The airline expects hell be home tomorrow. Hell be flying inside the passenger cabin this time with a human escort, and may be coming home first class. Jeff . Glor all right, good luck to irgo on the way back. Kris, thank you. When we come back here, toy story, the final chapter. 3, 2, 1. Not cool. Freezing away fat cells with coolsculpting . Now thats cool coolsculpting safely freezes and removes fat cells with little or no downtime. And no surgery. Results and Patient Experience may vary. Some rare side effects include temporary numbness, discomfort and swelling. Ask your doctor if coolsculpting is right for you and visit coolsculpting. Com today. For your chance to win a free treatment. And back pain made it hard to sleep and get up on time. Then i found aleve pm. The only one to combine a safe sleep aid. Plus the 12 hour pain relieving strength of aleve. Im back. Aleve pm for a better am. So lionel, what does 24 5 mean to you . Rade well, it means i can trade after the market closes. Its true. So all. Evening long. Ooh, so close. Yes, but also all. Night through its entirety. Come on, all. The time from sunset to sunrise. Right. But you can trade. From, from. From darkness to light. Youre not