MOSCOW (AP) - Investigators now say it wasn't a power surge that caused this morning's deadly subway train derailment in Moscow.
The derailment, deep below the city's streets, left at least 20 people dead and sent 150 others to the hospital -- many with serious injuries. The dead and injured had to be removed from twisted and mangled cars, which had been crowded with passengers at the height of the morning rush hour.
Officials had said earlier that a power surge triggered an alarm, causing the train to stop abruptly. They now are looking at whether there was a problem in one of the cars, or whether the roadbed had sunk.
Moscow's airports and transit systems have been a prime target for terrorists over the past two decades, but officials are vigorously dismissing terrorism as a possible cause.
In a video released by emergency officials, several wrecked train cars appeared to be almost coiled, occupying the entire width of the tunnel. Workers were trying to force open the mangled doors of one car to retrieve bodies. Survivors, meanwhile, walked along the tracks in the dimly-lit tunnel.
Technical glitches occur regularly in the Moscow Metro, but the system hasn't seen deadly accidents in decades.