NTSB: Amtrak train was traveling at more than 100 mph

NTSB: Amtrak train was traveling at more than 100 mph · CNBC

The Amtrak train that crashed in Philadelphia Tuesday night was traveling at more than 100 mph-double the posted limit-before it derailed, the National Transportation Safety Board said Wednesday.

The train was going 106 mph when its engineer applied emergency braking just seconds before the crash, said Robert Sumwalt, a board member of the NTSB. In a news conference Wednesday, he stressed that the agency could not conclude speed alone caused the accident.

The posted speed limit at the sharp left turn where the train derailed is 50 mph, lower than on either side of the curve. The area where the derailment occurred is known as Frankford Junction and lacks a speed control technology the NTSB has advocated, Sumwalt said.

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The train was headed to New York City from Washington when it derailed and tipped over in Philadelphia, mangling the front of it, killing at least seven people and injuring several more. Some passengers climbed out of windows to escape.

Philadelphia-area hospitals treated more than 200 patients after the derailment, officials said Wednesday, though they still do not have an accurate count of how many people remain missing.

The search site remains "very active," Philadelphia Mayor Michael Nutter said in a separate briefing Wednesday.

Samantha Phillips, the city's director of emergency management, told a news conference earlier Wednesday that officials were still trying to account for all of the people on the train's manifest, and she urged anyone who had been on the train and gotten off safely to contact Amtrak and register themselves.

As of Wednesday morning, some passengers were still reported to be missing. Rachel Jacobs, chief executive of online learning start-up ApprenNet, had been among the missing, but authorities later confirmed she was one of the fatalities.

Abid Gilani-a senior vice president at Wells Fargo- also died in the crash, the company said.

Nutter also said that the train's recorder-the rail equivalent of an aviation "black box"-had been recovered and was being analyzed by Amtrak in Delaware, though there was no information yet from the device.

Read More What Amtrak derailment means for Northeast travel

"We will continue to do all we can until we have accounted for all the people we believe were on that train," Nutter said.

Sumwalt said the event recorders and a forward-facing video camera in the front of the train will both potentially provide data on what went wrong.