Athletes. Is it safe . Nightly news begins right now. Announcer from nbc news World Headquarters in new york this is nbc nightly news with lester holt. Good evening. Right now fires are burning from one end of california to the other. The worst of them northwest of sacramento where at least 24 homes are destroyed, 6,000 structures are threatened and 13,000 people have been urged to gather up their belongings and head to safety. In all an incredible 9,000 firefighters are working more than 20 fires across the state. But the socalled rocky fire has proven the most dangerous and confounding, tripling in size over the weekend. Nbcs joe fryer is there with the latest. Rowdy good evening, lester. You can see we are surrounded by smoke from the rocky fire. 2,500 firefighters are now on the ground here. And weve heard from veterans whove been doing this 10 20 even 30 years who said they have never seen a fire behave like this one. The villain of Northern California is a massive agile wildfire that refuses to be contained. Condition thats were seeing on this fire are unprecedented. Very much a challenge for firefighters to try to predict when you have such erratic winds, winds that are changing throughout the day. And its always going to be something that were concerned with. They call it a dirty bush. These are backfires that arent quite finished yet. Firefighters are intentionally lighting all this dry brush on fire so if the big rocky fire comes over the hill well then theres nothing left to burn. With so much unpredictability i am scared. I really am scared. Rowdy . More than 13,000 people have been evacuated. They told us this is an unprecedented fire. It was everywhere. Huge. Last thursday the fire perimeter looked like this. But over the weekend it tripled in size. The fire has now burned 94 square miles. Thats almost the same size as californias capital, sacramento. Time lapse video taken last night from a vineyard shows the fire huffing and puffing, flames and smoke growing with every passing minute. Across california 9,000 firefighters are now battling more than 20 large wildfires. Four years into the drought thats fueling these flames theres hope an el nino winter will bring muchneeded rain but theres no guarantee. Most of the rain that gets impacted by el nino falls in Southern California but we really need it to fall in Northern California where all of our reservoirs are. For now all eyes are on the rocky fire which wont go down without a fight. More than 5,000 homes are threatened by this fire which has already destroyed two dozen homes. Firefighters are making progress. It is now 12 contained. Lester . All right. Joe fryer, thanks. From fire we go to floods and an emergency situation unfolding right now at the opposite end of the country. Flood waters so severe that mandatory evacuations have been ordered. Neighborhoods near tampa are underwater. Some people rescued from their homes by boat. The weather channels mike seidel is in Newport Richie florida. Central florida is drenched. Pounded by incessant rains caused by a stalled weather front. In 12 hours we picked up a months worth of rain. Here at Newport Richie the river has spilled into the streets. This neighborhood underwater. The only way out by boat. Officers helping residents get to dryer ground. There were mandatory evacuations including this palm harbor rv park where rescuers rescued people with military style vehicles. There was no ability for the earth to absorb this so it stays on the streets. Can we fix it . No. All the money in the world would not fix this problem. Reporter meanwhile, farther north cleanup continues across the midwest. Where outside chicago high winds toppled a tent at a town festival, killing one and injuring nearly 20. In iowa a huge tornado touched down near the town of lennox. And in michigan emergency crews worked to clear downed trees and restore power to more than 90,000 customers. Back here in the tampa bay area it has rained every day but one over the past three weeks. Over 47 inches so far this year. In miami where its usually wetter theyve had 26 inches less rainfall. Theyre in an extreme drought. Back here lester dryer weather and some of that florida sunshine that everyones looking forward to returning over the next couple of days. Mike seidel thanks very much. We have breaking news out of memphis right now where Authorities Say a suspected cop killer is now in custody. Tremaine willborn had been on the loose after allegedly gunning down officer shawn bolton on saturday. Our Kerry Sanders is on the story for us. Whats the latest . Reporter well lester sources tell nbc news after an extensive manhunt 29yearold willborn is in custody with the u. S. Marshals. Witnessed had identified him as the trigger man who as you said shot and killed Memphis Police officer shawn bolton. Call an ambulance. Call an ambulance reporter killed saturday night, Memphis Police officer sean bolton as he approached a car during a traffic stop. The driver jumped out and ran. But the passenger stayed behind and police say opened fire on officer bolton. The ambulance is already en route. Reporter as officer bolton lay dying in the street saturday an alert bystander grabbed his police radio and pleaded for help. Please please hurry up. Reporter the driver whod taken off running said he heard gunshots. While my clients running he hears six to eight gunshots. Reporter that driver, whose identity is being shielded is not charged with any crime. He turned himself in helped Police Identify the suspect as convicted bank robber Tremaine Wilbourne, a memphis native who is on parole from federal prison. Police sources here say Tremaine Wilbourn may have shot the officer because as a federal employee he was not allowed to have a gun and the officer would have likely found it during that traffic stop. Kerry sanders, thank you. Nbc news is learning new insight about the potential political stunt that could hak up the battle for the white house. Word that Vice President joe biden still mourning the death of his son beau just two months ago, is actively considering making a late entry into the democratic race to challenge hillary clinton, a challenge that beau biden strongly encouraged. Andrea mitchell has late details. Reporter at his home in delaware today joe biden was out of sight. Friends say taking care of his family dealing with his own grief, and sources tell nbc news tonight still undecided about whether to take on the political fight of his life. The dying wish of his son beau. My hero the jexnext Vice President of the United States joe biden. Reporter a hope echoed by his surviving son, hunter. Reporter biden supporters tell nbc news hes long felt Better Qualified to be president than hillary clinton, with whom he clashed over the use of force in libya and afghanistan. And tonight in a new nbc news wall street journal poll clinton is facing her worst numbers yet of this campaign. Just 37 of those questioned view her positively. 48 see her negatively. A sharp 15point swing since june. But the poll was taken after inaccurate reports that she was the target of a potential criminal investigation. All untrue. Supporters say a biden challenge could even help clinton. She was at her best in 2008 when she fell behind and then she came into ohio texas, pennsylvania and she was the underdog, and she rolled up her sleeves and let everyone know exactly what she believed in. Reporter to soften her image clinton will start airing gauzy tv ads in iowa and New Hampshire tomorrow. And now a new title. Grandma. Reporter getting in this late would be a challenge for biden. He ran twice before and failed. Hes never been a good fundraiser. And many of his former aides have already signed with clinton. Theres also those biden gaffes. This is a big [ muted ] deal. Reporter but now theres an outpouring of sympathy in a year where his middleclass appeal could Trump Campaign glitz. Hes genuine. Hes real. Hes a person of authenticity in a year that craves authenticity. How would the president choose between biden and clinton . Hillary clinton or joe biden . Love them both. Biden and president obama are very good friends, and im told the president has been frank in their weekly private lunches about how difficult running against clinton whos way ahead of the other democrats would be. Lester . Andrea, thank you. On the republican side the candidates are now on a collision course in New Hampshire. Nearly a dozen of them are in the battleground state tonight as they hurtle toward the first real test, the inaugural debate this week. Our Peter Alexander is in New Hampshire tonight. Hi, peter. Reporter lester good evening to you. Donald trump is skipping this voter forum here in New Hampshire tonight, confident hes going to be center stage at that First OfficialRepublican Debate this thursday in ohio. Its his brash style that has fueled his surge in the policy but its also backfiring. Heres our latest nbc news wall street journal poll that shows 61 of registered voters say they believe trump is hurting the republican partys image. Among registered republicans nearly half say trump is hurting the party. Trump also repeatedly vowed that he will win the latino vote but 75 of latinos say they have a negative view of him after those controversial comments he made about undocumented mexican immigrants. So who will join trump on stage . Right now the battle is for those final two spots. Down to the wire between Chris Christie rick perry, and Kasich John Kasich of ohio. Perry right now the odd man out. The lineup will officially be set tomorrow night. Lester . Peter alexander in New Hampshire. Thank you. An emotional plea today from actress and comedian amy schumer, choking up while speaking for the first time about the deadly shooting rampage that erupted during a showing of her new movie trainwreck in lafayette, louisiana. Schumer is teaming up with a powerful Family Member in a call for tighter gun control for violent criminals and the dangerously mentally ill. Our National Correspondent kate snow reports. I was dead sober. I had like two drinks. Three max. Reporter this is the amy schumer making us laugh in her new movie trainwreck. But at a press Conference Today with her cousin new york senator chuck schumer, a very different amy. Im not sure why this man chose my movie to end these two beautiful lives and injury nine others. But it was very personal for me. Reporter schumers voice faltered as she talked about the two women killed in that movie theater, Jillian Johnson and mayci breaux. When i heard about this news i was completely devastated and i wanted to just go down to louisiana and then i was angry. My heart goes out to jillian and mayci, to the survivors, to the families and everyone whos tied to this tragic senseless, and horrifying actions of this man, who shouldnt have been able to put his hands on a gun in the first place. Reporter today both schumers called for legislation that would strengthen background checks required to buy guns by rewarding states that accurately submit information to the background check system and penalizing states that dont. The critics scoff and say, well theres no way to stop crazy people from doing crazy things. But theyre wrong. There is a way to stop them. Reporter schumer says she expects a backlash. An nra spokesperson said late today while they havent seen the legislation senator schumer is proposing it sounds very much like existing law the nra supported, adding we all agree that people who are adjudicated mentally ill shouldnt have firearms. These are my first Public Comments on the issue of gun violence but i can promise you they will not be my last. Reporter a comedian speaking out on a topic thats deadly serious. Kate snow, nbc news, new york. There was a lot of emotion in washington today. In fact a rare moment at the white house. President obama got unexpectedly emotional as he unveiled a sweeping controversial plan to deal with Climate Change which he called one of the key challenges of our lifetime. Our Chris Jansing is at the white house for us with more. Chris . Reporter good evening, lester. President obama today made a passionate case for reducing Carbon Emissions, especially from coalburning power plants arguing that nothing less than our Health Safety and future are at stake. I dont want my grandkids not to be able to swim in hawaii or not to be able to climb a mountain and see a glacier because we didnt do something about it. I dont want millions of peoples lives disrupted and this world more dangerous because we didnt do something about it. Reporter the target of this plan is power plants. They produce more Carbon Emissions than cars airplanes, and homes combined. The thought to cut those emissions by 32 by 2030. And each state will have to figure out how to meet that goal. Already many states are gearing up to fight the plan in court. Other critics say it will cost jobs and your electric bill will go up. Claims the white house disputes. Its a fight that will likely continue after the president leaves office and may well end up in supreme court. Lester . 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If you have any sudden decrease or loss in hearing or vision or any symptoms of an allergic reaction stop taking cialis and get medical help right away. Why pause the moment . Ask your doctor about cialis for daily use. For a free 30tablet trial go to cialis. Com we are now just over the oneyear mark from the start of the summer Olympic Games in rio. But as the scramble is on to get venues ready, there is growing concern over Water Quality for the athletes. A new report says the water is rife with viruses that some experts say could pose a health hazard. Nbcs Miguel Almaguer is in rio with an upclose look at the situation. Reporter just below the soaring peak of Sugar Loaf Mountain and not far from the world famous copacabana beach theres trouble in the water. This is one of several water venues where some 1,400 olympians will compete. Biologist and environmental activist mario mascatelli says nearly 400 tons of garbage flow into guanabara bay every day. He says raw sewage from 8 Million People it turning some stretches of these tropical waters jet black. Oceanographer david zee says in the waters where sailors will compete researchers found samples of socalled super bacteria thats resistant to antibiotics. Would you let your children swim in this water . No. For sure not. The waters not safe enough is. Reporter according to an investigation by the associated press, a single virus reading in the lake tested up to 1. 7 million times whats considered hazardous on a Southern California beach. Brazilian officials challenged that reports methodology. The International OlympicCommittee Also said World Health Experts found no significant risk to athletes. But neither the brazilian government or the ioc has tested for viruses, only bacteria. U. S. Sailors tara tankin and helena skut are training in guanabara bay today. While their boat sailed into debris in rios waters last year they say thats not uncommon in regattas all over the world. I havent gotten sick. No problems so far. Reporte