A key piece of smiths case, the Pressure Trump put on his Vice President , mike pence, including a call on Christmas Day asking mr. Pence not to certify the results. Mr. Trump allegedly telling pence, quote, youre too honest. How pence reacted today. Our team in washington and our legal analysts standing by. Also tonight, the scare on capitol hill. Staffers running out of the Senate Office building after reports of an active shooter. Police later giving the allclear. What happened . The gunman who killed 11 people at a pittsburgh synagogue sentenced to death for the worst antisemitic attack in u. S. History. The disturbing images, a cinder block cell in an oregon home. The fbi says a kidnapped woman was kept inside but made a dramatic escape. Tonight the plea to the public for help. Are there more victims . And visitors flocking to a zoo in china after this video exploded on social media. Is that a bear or a human in disguise . Announcer this is Nbc Nightly News with lester holt. Good
back now with the alarming news about a critical water lifeline for the western u.s. a new study finding the colorado river basin has lost trillions of gallons over the years as temperatures rise. miguel almaguer with more in our series, climate challenge. reporter: as one of the nation s most precious resourceses contininues to dwiwindle, tonight a new study confirms what researchers long feared, over a period of 21 years, the vital colorado river basin has lost 10 trillion gallons of water due to warming temperatures. the staggering amount is enough to fill lake mead, the nation s largest reservoir which today is dangerously depleted. how concerned are you by what you ve seen? i would say that this is a wake-up call in terms of climate change s impact on water availability for the colorado basin. reporter: with human-caused climate change, greenhouse gases pushing temperatures up, the