The MTA released its initial findings on what caused the subway outage that lasted for several hours Sunday night.

Several passengers were left stranded when 83 trains across seven lines lost power.

Gov. Kathy Hochul called the incident “unacceptable,” a feeling echoed by many of the passengers who got caught in the mess, some climbing out of the cars and into the tunnels.

Rich Baez, who was stuck on the 2 train in the Bronx Sunday, says he chose to travel through the tunnels because he couldn’t sit in the hot subway car for much longer.

“After a while, people started arguing and fighting and being claustrophobic, so I took it upon myself to get out of there,” Baez says. “Multiple people were climbing off the train in the middle of the tunnel and walking on the tracks to get to the next station. We had to walk for about a quarter mile underground."

The MTA says service has been restored to the 1, 2, 3, 4, 5, 6 and L lines, but commuters should still expect delays.

According to the MTA, Con Edison experienced a “power anomaly” around 8:25 p.m. that impacted seven subway lines. It says backup emergency systems then failed to activate.

Additionally, the MTA says an alert system that was supposed to notify subway management of the failures did not work.

As a result, the MTA says the managers thought the systems were operating correctly when they were actually only relying on batteries, which are not meant for long-term use. It says the batteries cut at 9:14 p.m., causing the widespread service interruption.

A spokesperson from the Riders Alliance says the governor has to address the issues of old infrastructure and extreme weather affecting the transit system.

"New Yorkers depend on fast, frequent and reliable subway service. It’s not just the MTA here, Con Ed has a part to play, and the governor can really bring the parties together and work on a solution,” says Danny Pearlstein, the policy and communications director of the Rider's Alliance

MTA sources say two engineering firms will conduct an independent review and will make recommendations to try to prevent this in the future.

Gov. Kathy Hochul says the state is also in talks with Con Edison to get to the root of the problem.

“My message to the riders is this: We are working to find out the full extent of what went wrong, and we will fix it," Gov. Hochul says. "New Yorkers deserve absolute confidence in a fully functioning subway system, and I promise to do everything in my power to restore that confidence."

In a statement, Con Edison said, "A fault to an underground transmission feeder in Long Island City, Queens caused a momentary voltage disturbance last night. The disturbance lasted a fraction of a second for all customers throughout our service territory. We remain in contact with the MTA to understand why they lost this communication at their rail center during the voltage disturbance."