Six people died and 13 others were injured in an apartment fire in downtown Las Vegas of United States on Saturday morning, authorities say, reports CNN.

In a news release, the Las Vegas Fire and Rescue said firefighters arrived at the Alpine Motel Apartments after 4 am and found people jumping out of windows. Black smoke poured out of the wood frame, 42-unit building near Las Vegas Boulevard North.

Firefighters went inside and discovered the fire in an apartment. The fire started around a stove in that apartment and was accidental.

Residents told investigators the building didn’t have heat and some residents might have been using their stoves for heat, Las Vegas Fire spokesman Timothy Szymanski said.

Firefighters found three people dead inside the building, one dead on the sidewalk and two dead at an unspecified location, the news release said. Their identifies have not been released.

Of the 13 injured people, 10 were taken to hospitals for treatment. The building managers estimated 70 people lived there.

The fire is believed to be the worst fatal fire in the city’s history, according a news release. Damage is estimated at $475,000 and the incident remains under investigation.

The MGM Grand fire of November 1980 occurred outside the city limits. It killed 87 people and injured around 700.