The Green Line train that derailed at the beginning of October was going 36 mph in a 10 mph zone, the National Transportation Safety Board says.

The NTSB revealed new details about the derailment, including naming several factors that may have played a role, such as speed.

A preliminary report suggests that speed was likely a factor in a Green Line train derailment earlier this month, which resulted in a multiple-day closure.

A Green Line trolley was going more than three times the speed limit and failed to stop for a signal before derailing Oct. 1, officials said.

MBTA Green Line train that derailed, sending several riders to the hospital, was traveling 36 mph in a 10-mph zone: NTSB

The derailment occurred Oct. 1 during the afternoon commute. Seven passengers were taken to a local hospital with minor injuries.