New London — Extreme cold weather is being blamed for a stuck Amtrak bridge in New London that caused delays Thursday night for at least five  trains.

The Shaw’s Cove Bridge would not close and, as of 10 p.m., caused delays for Amtrak trains 179, with its 192 passengers; 94, with 293 on board; 2172, with 73 on board; 178, with 289 on board, and 67, with 135 on board. Some Shoreline East trains also were affected.

Amtrak engineers were working to close the bridge as quickly as possible so that service could resume, Amtrak spokeswoman Beth K. Toll said in an email earlier in the evening.

Before service was restored about 11 p.m., stuck passengers were venting their frustration on social media.

"Amtrak northeast regional train #94 is delayed in New London with no est time to resume," Twitter user Sandra Mehlmann wrote in a tweet.

On the same train, Arielle Smith, 32, of Manhattan said she was comfortable, despite the temperature hovering around 9 degrees outside, but bored.

Amtrak's official Twitter account urged them to call the company's customer service after their trip.

Smith said she was on her way to Boston to visit family for the long holiday weekend when the train stopped about 8:20 p.m., and she and her fellow passengers had been sitting for nearly two hours waiting for the bridge issue to be resolved. She said the trip from Penn Station in New York City to South Station in Boston, which she has made many times, usually takes about four and a half hours to make by train. She was scheduled to arrive at the Route 128 station in Boston at 9:50 p.m.

About 10:30 p.m., she was still waiting for the train to get moving again in New London. "We are still an hour and a half away from my stop, at least," she said.

Rail staff were keeping the passengers informed of the situation, she said, and they had handed out snacks and bottled water. "The WiFi is working. Bathrooms are working. Everyone is friendly," she added.

Things were not much better for those who were awaiting passengers scheduled to disembark and those hoping to catch a train in New London.

All but three people were left at Union Station in New London at 10 p.m. because of the protracted delays. The 7:38 p.m. Shoreline East train had yet to leave the station.

Most people had left, opting to buy a ticket for another day or finding an alternate means of transportation, said Rachel MacLellan, who was still waiting for her 8:24 p.m. train to Boston.

“I have to work in the morning,” she said.

MacLellan waited with her mother, Lorraine MacLellan of Niantic, and were keeping tabs on the phone updates from Amtrak that did not appear to be accurate. At 9 p.m. she received a text that the estimated time of arrival was 9:06 p.m.

The two planned to stick it out, hoping that the Amtrak attendant did not kick them out of the station at 10 p.m. An unidentified Amtrak employee, who declined comment, could be seen locking the doors but made no movement to order the trio out.

About 10:56 p.m., Toll sent an email saying the bridge had been closed and locked. "There may still be some residual delays as the trains get moving again," she said.

At 11 p.m., Smith sent a jubilant text from her train to The Day, "Second train just passed. And we are moving!"

Day Staff Writer Jacinta Meyers contributed to this report.

g.smith@theday.com