The TTC's Line 3 Scarborough RT service could permanently shut down earlier than expected after itsderailment incident on Monday night, according to the TTC.

Forty-five people were onboard the train during the derailment, which occurred around 7 p.m. near Kennedy and Ellesmere roads, just outside of Ellesmere Station. Although the cause is still unknown, the rear car on thesouthbound train separated from the rest of the trainand derailed.

Dozens evacuated and several injuries reported after TTC train derailshttps://t.co/pRMmG3R5gh#Toronto#TTC

— blogTO (@blogTO)July 25, 2023

Five people sustained minor injuries during the derailment, which ranged from severe bumps to bruises, and were transported to the hospital out of caution.

"When the train came off the tracks, they were obviously tossed and jostled, and you know some bangs and bumps and bruises and most likely some trepidation and anxiety," Deputy Fire Chief Jim Jessopp told reporters at the scene.

Following the incident, the TTC replaced Line 3 with shuttle buses from Kennedy to McCowan stations, and it's not clear if the line will return at all beforeits scheduled decommissionon Nov. 23, 2023.

The entire TTC Line 3 will be out of service for days after train derailmenthttps://t.co/JBeUBkSklM#Toronto#TTC

— blogTO (@blogTO)July 25, 2023

TTC spokesperson Stuart Greentold CBC Radio's Metro Morningthat internal conversations are happening about whether or not the TTC line will resume service before it's shuttered in the fall.

The line was already scheduled to be replaced by buses until the completion of theScarborough Subway Extension, which is currently slated for opening in 2030.

"The damage was significant. We need to know exactly what caused it. Was it something to do with age? Something to do with infrastructure? Was it the vehicle? All of that is under investigation. At this point we just don't know what caused it,"Green told CBC.

Although the TTC could technically move up the timeline to decommission the Scarborough RT early, the agency will still need some time to adequately replace the service with a reliable bus network.

"If we don't believe it's safe to restart train service, we would not restart it. We're having this conversation internally about whether or not we just leave it shut down,"Green told CP24.

TTC CEO Rick Learyalso provided a statement on Monday nightwhich revealed that an immediate review of the incident has been ordered using outside expertise as necessary.

"I know this will be an inconvenience to our customers, but it's the right thing to do," Leary said. "I apologize to all those impacted by the incident."