The O-Train that derailed less than two weeks ago near Carleton University is likely staying off the tracks for good.

The incident happened at about 3:30 p.m. on August 11, 2014. A female passenger was injured and taken to hospital with neck and back pain.

CTV News has learned that the derailed O-Train is now out of commission and two operators have been placed on leave.

“Right away, the member is put off on investigatory leave and that’s more for then member and also for the investigation,” says Craig Watson, President of the Amalgamated Transit Union.

Both members are full-time operators of the O-Train with a lot of experience.

OC Transpo is leading the investigation into the derailment but will forward its findings to the Transportation Safety Board for review.

Two likely causes: A switch in the track that splits it from one to two was left slightly open and the operator failed to exit the O-Train to inspect it.

“They're technically supposed to inspect the switching gear, switching system, unfortunately they didn't do that. So we're looking into why that occurred,” says John Manconi, OC Transpo President.

Sources say the derailed train will likely remain out of commission. Manconi says experts will be brought in to offer advice, but the main priority is keeping the two existing trains running and getting a newly purchased fleet of trains ready for service.

Currently at full service, two trains run at any given time. The third is a substitute in the case of mechanical failures or maintenance.

“We just don’t have a backup train. So if there was to be an absolute breakdown service maybe have to be reduced and we might have to put buses on,” says Craig Watson.

Carleton University student Ali Atwy says with fall classes around the corner, having no backup makes him nervous.

“It would be nice if there was a third train, just so I feel a lot more like it's reliable,” he says.

With a report from CTV’s John Hua