Shannen McCartney and her boyfriend had a whirlwind romantic night at a Boston museum all planned out for their six-month anniversary.

Instead, she spent her anniversary in tears, huddled in her jacket on a disabled and chilly Downeaster train, eating a club sandwich.

“It was an absolutely terrible day,” McCartney, of Portland, said Friday. “We both shed tears and tried to joke about it. If we’d known we’d be sitting there for five hours, we would have brought an iPad, a bottle of wine or even dinner.”

McCartney was one of 25 people aboard a southbound train that broke down in North Berwick around 3:30 p.m. Thursday, idling there until another southbound Downeaster train came along and pushed it to Boston, an ordeal that ended with passengers finally getting off both trains about 11:30 p.m.

Amtrak officials said Friday that the train’s traction motor failed, possibly because of the snowy weather.

“The traction motor can become packed with snow and short out,” Amtrak spokeswoman Christina Leeds said Friday. “It could be something caused by snow, but we haven’t verified that.”

The Downeaster’s website warned Friday that other trains were being delayed by the snow, and that there would be reduced Downeaster service Saturday and Sunday because a major snowstorm was predicted for the weekend.

Passengers on the stranded train said they were angry they couldn’t get more complete information about the delay.

For the first few hours of waiting, McCartney said, the electricity on the train kept going on and off while the crew tried to restart the engines. The cars got colder as the sun went down, even though the idling train still had electricity and heat.

After about two hours, workers told passengers that another train was coming to push them the rest of the way to Boston.

“We weren’t told a single thing” until then, said McCartney, who read about the breakdown on the Portland Press Herald’s website while sitting on the train, and got more information by texting with a friend who was aboard the train that was coming to push them to Boston.

“Currently on this train! Completely ruined our Valentine’s night at The Boston Children’s Museum Adult Night,” McCartney wrote on Facebook as she waited on board. “Send Carrier Pigeons for entertainment, please.”

Fellow passenger Jessica LaJoie said she had spent about $1,000 planning a big night out in Boston, which included dinner, seeing Sam Hunt play at the House of Blues with a friend and spending the night at a hotel. They missed the show, and all the restaurants were closed by the time they got to the hotel.

“We ordered room service,” LaJoie said.

It was worse for McCartney and her boyfriend, Kyle Dixon. They didn’t have plans to spend the night in Boston, so after they finally arrived, they went into the terminal for a few minutes before turning around and boarding the next northbound Downeaster to go right back to Portland, arriving about 3:30 a.m.

“It was a total of 13 hours being on the train,” she said. “I was very upset. It was a lot of tears.”

At one point during the wait, LaJoie said, she asked the train workers if they could just get off the train and walk to a nearby road where they could see cars passing.

“They wouldn’t let anyone off because of the snow,” said LaJoie, who lives in Brunswick and works as a medical assistant at Martin’s Point Health Care.

Passengers passed the time talking and playing games, LaJoie said, and they were offered free food and non-alcoholic drinks.

LaJoie and McCartney wondered why, because the passengers were near a road, Amtrak didn’t just send a bus to get them off the train. Officials had said they couldn’t use a bus because they didn’t have access to a road.

LaJoie and McCartney said they weren’t impressed with Amtrak’s compensation for their trouble: a voucher for a one-way Downeaster trip that expires in April.

“I understand that these things happen, especially with such a harsh winter that we have endured,” LaJoie wrote in an email sent late Thursday. “The poor customer service of Amtrak has left a bad impression. … (I) feel let down with the lack of understanding or compensation.”

Leeds said compensation is given on a case-by-case basis, depending on the circumstances.