On Thursday, a major fire engulfed a 33-story South Korean residential high-rise, causing firefighters to evacuate hundreds of residents.

Horrified citizens scrambled to the roof of Ulsan’s Samhwan Art Nouveau building to avoid the flames, the Yonhap News Agency reported, as slabs of burning concrete rained on the street below.

At least 15 people were rushed to hospitals, and 43, according to the Ulsan Fire Department, were evacuated from the rooftop of the 334-foot structure.

“Suddenly, there was a burn. One witness told the outlet that the windows were smashed and the living room and bedroom were lit up.

Around 11 p.m., the stunning blaze presumably started on the 12th floor of the house. local time, fire officials said. The high rise contains 120 apartments and several commercial units.

Several hours later, the fire was confirmed extinguished.

According to firefighters, who said they managed to evacuate several residents out before the fire grew out of control, it was not immediately clear whether anyone had died inside the house. Firefighters were also checking inside the tower for suspected casualties Friday morning, officials said.

As smoke billowed into the sky and burning rubble dropped to the ground, the spectacular video shows quick-moving flames climbing to the roof of the house.

To prevent the inhalation of hot smoke, occupants of the building were also seen running outside, some of them barefoot, with towels over their faces.

Fueled by high winds, the fire, according to authorities, rapidly spread to the roof of the building and down the block.

Fire authorities said all 136 residences on the block were evacuated and at least 77 persons were treated for smoke inhalation.

The blaze also extended at one point to a neighboring shopping center in Ulsan’s Dal Dong district, near the southern city of Busan. They put out the fires a few hours before the house. One onlooker told local media outlet YTN News that “exterior content” added to the outside of the house, probably insulation, may have caused the fire to spread rapidly.

Others said they were trying unsuccessfully to get hold of members of the family who lived nearby.

The event occurred just like the structure fire that in January tore through a 25-story high residential rise in LA.

In that scenario, the Barrington Plaza fire sent hundreds of people to evacuate by climbing from the windows and up to the roof. As a consequence of the wildfire, eleven people were wounded and seven were hospitalized.