At least 14 people were hurt — three of them seriously — when an escalator at a busy South Korean subway station unexpectedly reversed direction, hurling riders to the ground. 

Security video captured the heart-stopping moment an escalator at the bustling Sunae station in Bundang, south of the capital of Seoul in Gyeonggi Province, went rogue during the Thursday morning rush-hour, according to The Korea Herald.

In the recording, the moving staircase, which is supposed to be going up, abruptly starts going down, sending panicked riders plummeting downstairs and ending up in a human pile forming at the base of the escalator.

One person is seen falling over to the adjacent escalator.

The South Korean Fire Service received calls about the accident at 8:20 a.m. local time.

Police and fire officials said three people were hospitalized with serious injuries to the back and legs. Eleven others were treated for minor injuries.

Photos taken at the scene show first responders administering first aid to the victims, including a woman lying prostrate on the floor at Exit No. 2 at the station.

The malfunctioning escalator was later cordoned off, and the fire department said it plans to investigate the cause of the accident.

“I thought people were filming a disaster movie after seeing so many people crowded around the fenced exit,” a 68-year-old resident told the news outlet Korea JoongAng Daily.

A maintenance company conducted a monthly inspection on the escalator in May and reported no issues.

The Korea Elevator Safety Agency separately inspects escalators once a year.

The Railroad Special Judicial Police Unit under the Ministry of Land, Infrastructure and Transport will be in charge of getting to the bottom of the accident.  

“Authorities, including the fire services, are currently looking into the cause of the accident,” Gyeonggi Gov. Kim Dong-yeon tweeted Thursday. “We will investigate thoroughly so that no similar accidents occur.”