The Amtrak train that derailed Tuesday night in Philadelphia was traveling at "more than 100 miles an hour" before entering a curve where it crashed, according to The Wall Street Journal. The speed limit in that area is 50 mph.
The derailment killed at least seven people and injured hundreds. In a press conference Wednesday morning, officials said it was too early to offer a potential cause for the accident. Investigators recovered the train's black box, though, and are probing the incident.