No injuries were reported but the People Mover is out of commission for repairs.
Police say it hit a platform and is off the track. About 20 people were aboard at the time of the derailment.
Although police say the accident happened at 9:15, witness Brionne Jones said it was about 10:10 p.m.
Jones, in an e-mail, said the experience was scary for all aboard.
"We really thought the train was going to go over the track and crash to the ground," she said.
Jones, 22, and from Harper Woods, said that she believed the People Mover "hit the station."
Both she and her brother Raymond Jones, were Detroit Receiving Hospital getting treatment for minor injuries.
She said Raymond hit his head but is okay and she hit her knee on a pole and was waiting for X-ray results.
Detroit police say that the People Mover has its own technicians who will be called out. The timetable for repairs was initially unknown.
UPDATE: The Detroit People Mover reopened Friday just before 8 a.m.