FAIRFIELD, Conn. (WWLP) - Investigators looking into the collision of two trains in Connecticut are studying a rail fracture on the tracks as they try to find the cause.
The National Transportation Safety Board says a portion of the track will be sent to a lab for analysis.
It's not clear if the accident caused the fracture or if the rail was broken before the crash.
72 people were sent to the hospital Friday evening after a Metro-North train heading east from New York City derailed and was hit by a train heading west from New Haven.
The investigation will take at least a week.
Other areas of interest include the brakes and the performance of each train.