Note: Network broadcasts are subject to change due to breaking news events in Boston. Here's what we know so far about Boston news specials airing tonight.
Chasing Ice (8pm, National Geographic Channel) - An award-winning 90-minute documentary in which environmental reporter and former climate-change skeptic James Balog uses time-lapse techniques to document the rapidly changing Arctic landscape. The videos are the result of Balog's three-year mission to gather undeniable footage of the effects of global warming.
Nikita (8pm, CW) - Nikita is drugged and subjected to Amanda's mental-conditioning process. Meanwhile, Birkhoff and Sean attempt to save the women they love.
Happy Endings (8:30pm, ABC) - Max's former roommate, whose life he ruined, seeks revenge, but realizes that Max's life is so sad it's not worth wrecking. Max then sets out to get his act together with help from Jane. (Note: A new episode also airs at 8).
Vegas (9pm, CBS) - Katherine arrests Dixon after Violet accuses him of assault, while Lena finds the body of a gambler in a suite at the Savoy.
Grimm (9pm, NBC) - A volcano threatens to bury Portland in lava, while Adalind gains a new ally,
Shark Tank (9pm, ABC) - A self-described geek with an idea for made-to-order furniture, and an update on "Scrub Daddy" from Season 4.
Real Time with Bill Maher (10pm, HBO) - Dan Neil, a local automotive columnist who writes for the Wall Street Journal, will be among Maher's guests.