Two drunk women toppled off a Brooklyn subway platform and under a train — killing one — as horrified bystanders heard their screams early Sunday, cops and a witness said.

The young women were coming from a holiday party where they had been drinking heavily when they got off a southbound A train at the Broadway Junction station around 12:20 a.m., according to law-enforcement sources.

Both were wearing high heels and were “visibly intoxicated,” said witness Kwame Martin, 33.

“They were arm in arm and one of them stumbled back and fell in between two train cars,” he said.

“Her friend tried to catch her but the weight was too much for her and they both fell on the tracks between the two train cars. Then the A train started leaving the station.”

Martin added, “You could hear them screaming as the train rode over them. You could hear bones crunching.”

Law-enforcement sources offered a nearly identical account, saying the women “appeared to be highly intoxicated” and were staggering on the platform before one lost her footing and fell between the train’s third and fourth cars.

“It looked like one tried to grab the other,” a source said.

Martin said people on the platform desperately tried to keep the train from pulling out and crushing the women.

“Honestly, it was terrible. Everyone’s initial reaction was to bang on the train to alert everyone inside to hit the emergency red button,” he said.

The conductor activated the emergency brake at 12:21 a.m. when he saw the women fall between two cars as the train was leaving the station, an MTA source said.

Cops “came immediately, because there’s a precinct in the train station,” Martin said, adding, “You could hear [the women] moaning under the train.

When the FDNY and EMS arrived, “they took the train apart to get under and remove the bodies,” he said.

One woman, 23, was pronounced dead at the scene by paramedics, the NYPD said. Her identity was being withheld pending notification of her family.

The other woman, identified by sources as Jennifer Fuentes, 24, suffered an injured arm and was taken to Brookdale University Hospital Medical Center in stable condition.

A man identified by sources as Fuentes’ boyfriend declined to comment after visiting her in the hospital Sunday morning.

Martin, a software engineer who lives in Bedford-Stuyvesant, said the grisly mishap incident left him “definitely shaken up.”

Subway riders at the station called for additional safety measures, with a woman who identified herself as 25-year-old Allegresse, saying that she’d been to China, “where there are walls between people and the tracks, and they don’t have accidents like this.”

LaJuan Wix, 46, agreed, saying, “The MTA needs to start thinking about ways to improve the trains to make them more modern and avoid these accidents.”

Additional reporting by David Meyer, Kevin Sheehan, Rachel Green