Monday night's New Jersey Transit meltdown threw passengers into chaos and multi-hour commutes — including at least one train that was left waiting outside Penn Station for four hours. A passenger on that train said he eventually called 911 to remind them they were still there.

In the Facebook page NJT Riders Revolt, commenter Matty Lloyd said he boarded train #3510 at Secaucus Junction shortly after 6 p.m. Monday bound for Penn Station. The train was held for an hour outside of Secaucus, returned to Secaucus, then finally went to Manhattan — only to idle in the tunnel outside Penn for hours.

"They basically parked us right outside the tunnel as we watched trains leaving and going into NYC. There were even empty, lights out NJT trains being sent past us," Lloyd wrote. "At 9:10 they told us we would be the next train in and then (I) finally cracked and called the cops at 9:40 when we (sat) there for another 30 minutes."'

Lloyd said a woman on his train had a medical emergency and was taken off when the train returned to Secaucus. After that, it appeared he and his fellow passengers were forgotten.

"They forgot us on the train.... after four hours (I) called police who connected me to NJT.... they believed all trains were resolved and ours was in the yard," Lloyd wrote in a follow-up post. "They don't even know where trains are. After I called they contacted Amtrak and realized we were still left on the rails."

NJ Transit disputed losing Lloyd's train in a statement Tuesday: "NJ TRANSIT was aware of all train locations throughout last night’s delays. The Amtrak power issues resulted in significant delays to all trains in and out of PSNY with several trains, including 3510, experiencing long wait times, as trains were backed out of the tunnel and rerouted to tracks unaffected by the power issue," said Nancy Snyder, NJ Transit's Chief Communications Officer, in an emailed statement.

Another passenger also documented the unfolding drama on social media:

Stories being swapped range from sick dog with no one to walk him to $250+ ranger tix going to waste. People of all walks of life unified in their utter hatred of all things #njtransit @NJTransit @NY1 @Gothamist @amNewYork @CurbedNY @NJTransitFAIL — rrb (@richrobBOB) February 4, 2020

Laura Monahan, 34, of Williamsburg was aboard what seems to be the same train, which she said came to a halt in the tunnel outside Secaucus for an hour and a half. "First they made announcements — they said it was a disabled train and then they said it was overhead wires from Amtrak or something. And then they were like, okay, we have to back out because there's no power at Penn Station," Monahan told Gothamist on Tuesday. "And then they backed us out of the tunnel, and then we sat in between Secaucus and the tunnel for maybe 40 minutes or maybe another hour. I felt like I was starting to lose track of time."

@NJTRANSIT @StewartMader train just left secaucus again to go to penn and is now stopped. No announcements. What is wrong with you people? — Laura (@_agent355) February 4, 2020

She ultimately got to Penn Station at 10 p.m., nearly four hours after she first left Secaucus. The trip is typically around 15 minutes.

She noted that train personnel in the front and back of the trains could not seem to communicate throughout the trip.

"They just really New Jersey'ed the shit out of it. They're always not great, but it was really another level of insanity," Monahan said.

"Its clear they have (zero) ability to track or verify where these trains are," Lloyd wrote on Facebook. "It's 2020 and NJT lost a train between Secaucus and Penn station."

The reason for all the chaos, NJ Transit said, is Amtrak: "NJ TRANSIT trains experienced significant delays in and out of Penn Station New York last night while Amtrak worked diligently to resolve a power issue," Snyder said in the statement. "Our region is currently dependent on two century-old tunnels into and out of New York City, and incidents like last night only underscore the urgent need for additional tunnels. The number of trains operating in and out of New York drops by 75% when one of the tunnels is out of service, which makes recovery from delays much more difficult and lengthy."

Meanwhile, commuters geared up for more of the same Tuesday: