SACRAMENTO (CBS13/AP) – Authorities are investigating a crash that injured 27 people when Sacramento light rail commuter train struck a maintenance train.

Sacramento Regional Transit spokeswoman Devra Selenis says Friday that the maintenance train was not moving when the crash happened late Thursday.

Selenis says there were 24 people on the passenger train and three on the maintenance train.

Thirteen people were taken to hospitals, one with moderate injuries and 12 with minor injuries.

Sacramento Fire Department spokesman Keith Wade said late Thursday that 14 other people were treated at the scene and released.

Selenis says authorities are investigating to determine the cause.

The NTSB says they are sending six investigators to the scene of the crash. The investigators are expected to get to Sacramento later on Friday.

A bus bridge will be in place between Roseville Road and the Marconi light rail stations for most of the day, SacRT says.

Both the California Public Utilities Commission and SacRT will be doing their own independent investigations into the crash. SacRT notes that this is only the second time in 32 years that this kind of incident happened.

Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.