Train officials say all eight cars involved in Thursday’s derailment in Queens have been put back on their tracks. 

“Tremendous progress has been made” after a Long Island Rail Road train derailed near the Jamaica station, MTA chairman and CEO Janno Lieber said at a news conference Friday.

Officials said the accident injured 13 passengers and caused delays and service changes that are expected to last through the weekend.

“This is an area which normally gets 367 trains a day. It’s one of the busiest parts of the railroad. And we ran almost all those trains in the last 24 hours,” Lieber said. “Amazing recovery by our Long Island Rail Road operations."

Restoration will be a “24/7 operation” that continues through the weekend in order for normal service to return by Monday morning’s rush, Lieber said.

He said 1,600 feet of track have been “obliterated,” 900 feet of electric traction power restored and a third rail is being replaced.

He added that 400 concrete railroad ties will need to be “wiped out and replaced.”

As of Friday afternoon, eastbound trains are bypassing Hollis and Queens Village, as well as the LIRR employee-only Hillside stop, in the derailment's aftermath, Lieber said.

There is limited bus service, and NYC Transit is cross-honoring on the Q2, Q3, Q8 and Q110 buses for service between Jamaica and Queens Village.

The MTA is advising riders to check the TrainTime app and mta.info for the latest service updates.

Despite service changes on Friday’s morning commute, Lieber says the MTA had “86% on time performance.”

“Not where we wanted to be but on a day where we lost a huge portion of the railroad, an amazing accomplishment,” he said.

Lieber said the investigation of this incident continues as the derailment occurred in “haul interlocking,” a network of signals and tracks that allows trains to switch direction.

The agency is reviewing external video captured by the train and conducting ongoing interviews with train personnel.

Lieber said speed was not a factor in the derailment, as the train was operating at 54 mph, which is under the maximum allowed speed in the area.