LONG ISLAND CITY, Queens (WABC) -- New York Governor Kathy Hochul said Monday an "unprecedented system breakdown" led to half of the nation's largest subway system losing power Sunday night, stranding hundreds of riders and crippling service for hours.
Governor Hochul called the outage "unacceptable" and told the riders who found themselves stranded, "the system failed you." She's now calling for an internal investigation into the failure.
In a statement, Hochul says that the MTA "uncovered a sequence of failures that resulted in some backup systems not providing power as designed last night."
Among those failures was an inability to "quickly diagnose the underlying cause."
"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. New Yorkers deserve absolute confidence in a fully functioning subway system, and I promise to do everything in my power to restore that confidence," Hochul said.
The series of events started at 8:25 p.m. when a Con Ed power surge forced the subway's signal system to switch to back up power, impacting seven subway lines. That secondary power supply held until about 9:10 p.m. when it mysteriously failed, an MTA spokesperson said, disabling signaling for all of the numbered trains as well as the L train.
Con Ed said a fault to an underground transmission feeder in Long Island City, Queens, is what caused the momentary voltage disturbance.
"The disturbance lasted a fraction of a second for all customers throughout our service territory," Con Ed said in a statement. "We remain in contact with the MTA to understand why they lost this communication at their rail center during the voltage disturbance."
An MTA spokesman said the outage did not affect the subway's third rail, which powers the individual cars. That means that people stuck on the trains still had lights and air conditioning, until some riders opted to self-evacuate into tunnels.
That added to the chaos, forcing the MTA to cut the power to four trains clustered around 149th St. Grand Concourse, leaving those riders in the dark without air conditioning.
Service was fully restored by 1:29 a.m on Monday.
A preliminary investigation found that the two backup emergency generators are designed to operate automatically when it senses a loss of power, which would replace the battery power. The system is designed to return to Con Edison power when it becomes available, but that did not occur.
An alert system that should have informed subway management of the failures did not provide alerts, resulting in those managers believing that systems were operating properly when in fact batteries continued to energize the system for approximately 45 minutes.
At 9:14 p.m. the batteries, which are not designed to provide long-term power, ran out causing the major service interruption.
At a press conference Monday morning outside MTA Headquarters in Lower Manhattan, Governor Hochul said more than 500 people either had to be evacuated or chose to self-evacuate, opting to leave trains on their own, navigating dark tunnels. With the third rail still active, she called that "dangerous" and urged people not to do that if it happened in the future.
Mayor Bill de Blasio said he admires the 'do it yourself' attitude of New Yorkers, but also urged them to never self-evacuate from a subway train. He called the whole incident a strange series of events.
"This was a strange serious of events to say the least," he said. "We don't know how they all interconnect, but we've got to know. We need Con Ed to come clean with everything that happened, we need MTA to explain everything that happened over there. We don't know how much of this is Con Ed, how much is MTA, we don't how they connect."
Video from inside the 149th St. Grand Concourse station showed FDNY firefighters lifting people up off the tracks and onto the station platform. Riders told Eyewitness News they had little communication from the MTA.
"They kept saying they don't know what's going on. But an hour and 36 minutes we were trapped on the train. A long time. Kids, children, no water, nothing," one woman said.
Now, the MTA will conduct an "after-action" report to determine why the system failed. It is bringing in outside experts to conduct a full investigation.
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