A commuter train derailed in Chicago on Tuesday, as it approached the 95th Street Red Line station, according to Chicago Transit Authority spokeswoman Sheila Gregory.

The four-car train had 14 passengers in it, and one of them had minor-injuries, Gregory said.

It is unclear why the derailment happened, authorities said. All four cars remained upright.

Last week, a similar train derailed in Chicago, injuring 14. Authorities blamed that incident on the train's operator, FOX news reported.