Both engines on TransAsia flight stopped; death toll rises to 40 by Jack Rogers

http://www.cnn.com/2015/02/07/asia/taiwan-transasia-plane-crash/?iid=ob_tablet_article_organicsidebar_expansion&iref=obnetwork

The death toll from a TransAsia Airways plane crash in Taiwan rose to 40 on Saturday, authorities said, as details emerged that both engines lost power.Flight 235 crashed into a river in Taiwan's capital, Taipei, shortly after takeoff Wednesday with 58 people on board.Three others remain unaccounted for, while 15 people survived, authorities said.As crews search for the missing, more revelations emerged on what led to the tragedy.Pilots grappled with engine problems before the plane clipped a bridge and plunged into a river, Taiwan's aviation safety agency said.During the crisis in the cockpit, the pilots received a series of alerts, starting with an alarm related to one of the engines and followed by five stall warnings as the plane lost thrust.

I'm not sure if they knew about the engine failure from the beginning but if they did why would they even try to take off thinking it was nothing risking so many lives for this and why would the crew turn off the second engine if it's the only thing they got keeping them in the air?.