The engineer of the Amtrak train that derailed Tuesday night has been released from the hospital and was identified Wednesday as Brandon Bostian.
Einstein Medical Center in Philadelphia confirmed the identification of Bostian, 32, of Forest Hills, New York, in Queens, after other sources named him to NBC News. Philadelphia police said Wednesday night that he had been interviewed and had given a blood sample.
The National Transportation Safety Board said the train derailed when engineer slammed on the emergency brakes as it went through a curve in north Philadelphia at 106 mph — more than double the 50-mph speed limit. The crash killed at least seven people and injured scores of others.
Records of the Brotherhood of Locomotive Engineers and Trainmen indicate that Bostian has worked for Amtrak since April 2009. Caltrain, a commuter rail line in the San Francisco Bay area, told NBC Bay Area that Bostian worked for it several years ago, but it wasn't clear in what capacity.

IN-DEPTH
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SOCIAL
Chelsea Damberg and Richard Esposito of NBC News contributed to this report.