The Long Island Rail Road on Friday apologized to its customers for Wednesday morning's rush-hour service disruption and vowed to fully review how it communicated with customers throughout.

The railroad offered "an explanation and an apology for the events of September 2, 2015" in a message posted on its website and sent to customers via email and over social media.

A power outage that affected the railroad's signal system just outside the East River tunnels in Queens caused the disruption, according to the statement. That led to a 90-minute suspension of service into and out of Manhattan's Penn Station and delays of nearly three hours for some trains.

"To compound matters," a backup power source also failed, the LIRR said.

The service meltdown affected tens of thousands of commuters on the nation's oldest commuter railroad.

"We apologize for the difficulty experienced by our customers as a result of Wednesday's service disruption," the LIRR said. "We regret that because we could not estimate when the signal power problem would be resolved or trains would again be moving, our communication efforts did not live up to either our customers' expectations or our own standards."

LIRR Commuter Council chairman Mark Epstein expressed appreciation for the apology and explanation but said the LIRR must address the important question "Where do we go from here?"

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He called on the railroad to conduct a thorough review of its customer communication strategy, including how information gets to train conductors to pass along to riders.

"This is an opportunity now to take stock of the entire system -- top to bottom," Epstein said.

The LIRR, which completed permanent repairs Thursday night, said it is conducting "a thorough internal review of the events" to prevent a recurrence and strengthen backup power sources for its signal system.

"Decisions about service delivery that morning and communication efforts are also being scrutinized," the LIRR said in its statement. "The LIRR is committed to providing safe, secure and reliable train service to our customers, and we will continue doing everything possible to improve our operation."