Bloomberg info
"U.S. radar data and witness accounts support early reports that bird strikes may have forced a US Airways Group Inc. plane’s “miracle on the Hudson” splashdown this week in which all 155 people on board survived.
The plane intersected “a string of primary targets” that may have been birds at an altitude of 2,900 to 3,000 feet, 90 seconds after takeoff from New York’s LaGuardia Airport, said Kitty Higgins, a National Transportation Safety Board member."
Considering the max altitude of the plane was aprox 3200 ft it therefore sounds like the power loss must have been almost immediate and almost total