fb-pixel

The MBTA on Thursday ruled out operator error as the cause of the train car derailment that has wreaked havoc on Red Line commutes this week, while Governor Charlie Baker warned it would be several more days before the agency knows when it can fully restore service.

The agency told Red Line riders to expect slower commutes, and suggested delays may continue into the weekend as it tries to repair racks of electronic signaling equipment that were damaged by the train as it jumped the tracks outside the JFK/UMass Station early Tuesday.

“I’m not going to speak to when service will get back to normal because they are still doing the investigation on the Red Line with respect to both what caused it in the first place and what it’s going to take to fix it,” Baker said Thursday.

Advertisement



Baker added that officials “are not going to know the answer to the question about when for probably several more days as they continue to review the damage that was done.”

Massachusetts Bay Transportation Authority officials had previously warned riders to expect delays until at least Friday.

The cause of the derailment remains under investigation, and the cost of the incident has yet to be determined, MBTA spokesman Joe Pesaturo said in an e-mail Thursday.

However, Pesaturo did say the agency has determined that the operator of the Red Line train was not at fault. In a separate derailment of a Green Line trolley last Saturday, the agency has tentatively identified an operator error as the cause.

The operator of the derailed Red Line train, who was hired in 2016 and has a good record with no prior incidents or discipline, remains “out of service while the investigation advances,” according to Pesaturo.

In addition to ruling out operator error, T officials have determined that “the derailment was not caused by anything of a suspicious nor criminal nature,’’ Pesaturo said.

Advertisement



The agency said the train traveled some 1,800 feet — more than one-third of a mile — with one of its cars off the rails. One person suffered a minor injury, but did not require hospitalization.

The T gave an update Thursday on repairs, saying that all sections of damaged track and third rail had been fixed. Crews were also progressing on repairs to wires and cables in the area of the JFK/UMass stop.

Braintree branch customers still needed to change trains at that station on Thursday, but all Red Line riders passing through that stop were told to brace for an additional 20 minutes to their commutes. Many Red Line commuters again took to social media to vent frustration over crowded platforms, jammed cars, and slow commutes.

The derailment caused heavy damage to a “specific switch and signals area” at JFK/UMass, where the Ashmont and Braintree branches split, the T said in its notice to riders. Work in that area continued on Thursday. The T said it would provide a schedule update on Sunday regarding “Braintree branch service resuming through JFK/UMass.”

Pesaturo indicated that the T is examining at least six months of maintenance records on the derailed car, which was brought into service in 1969. Seventy train cars from that era are still in the T’s fleet, according to Pesaturo. The wheels of the train car did not come off during the derailment, he said in the e-mail.

Advertisement



Boston City Councilor Michelle Wu on Thursday criticized the T and said she thinks it should take more responsibility.

“Riders have reached a breaking point, and the refusal to acknowledge how dire the situation is is even more frustrating than the ongoing delays and inconveniences that will be caused by needing to fix the infrastructure,” she said.

Wu said that whatever the exact cause of the derailment, “we know that aging infrastructure is at the foundation of it.”

She said more money could be key to helping the MBTA improve, but she opposes the scheduled July 1 fare increase. Earlier this year, the MBTA’s governing board voted to increase fares by about 6 percent, while freezing rates for bus riders, seniors, and riders with disabilities.

“This week has highlighted that on top of the ongoing overcrowding, unpredictability, inaccessibility, we now have to worry about safety as well,” Wu said. “And riders can’t be asked to pay more for that.”

Tuesday’s derailment prompted Kyle Andrews, a 19-year-old student at the Wentworth Institute of Technology, to begin collecting signatures in a petition to freeze the rate hikes. Andrews said that he has collected more than 2,000 signatures and that the outrage he’s heard from riders has been universal.

“There’s a lack of transparency from the MBTA about this incident, and quite frankly, people are getting sick and tired of it,” Andrews said.

Another Wentworth student behind the petition, Gregory Simoneau, said the derailment was “a huge catalyst for a lot of people demanding change and demanding action.” Simoneau, 22, lives near JFK/UMass and missed class because of the derailment and its aftermath, he said.

Advertisement



“If we can maybe get the conversation started, get the ball rolling, then it helps us feel a little bit more that there’s something getting done,” Simoneau said of the petition.


Adam Vaccaro and John R. Ellement of the Globe staff contributed to this report. Danny McDonald can be reached at daniel.mcdonald@globe.com. Follow him on Twitter @Danny__McDonald.