CHICAGO (CBS) — A fire that left three young children dead at an apartment complex Friday night in northwest Indiana was intentionally set, authorities claim.

Crews responded at 11:26 p.m. to the blaze in one unit of the Oak Knoll Renaissance apartment complex in the 4400 block of West 23rd Court in Gary, according to the Gary Fire Department.

One woman jumped from a second-story window to escape the flames and heavy smoke, fire officials said.

Once the fire was brought under control nearly an hour later, firefighters found two of her children dead in separate beds on the second floor, and a third child dead on a staircase, fire officials said.

The Lake County coroner’s office identified a girl and boy as 4-year-old Alaya Pickens and 5-year-old Jayden Mitchell. They lived in the 3500 block of West 20th Avenue in Gary. On Monday, the coroner’s office identified the third child as 2-year-old girl Yaleah Cohen, who lived in the apartment where she died.

Three young children die in Gary apartment fire (Family Photo provided)

Three young children die in Gary apartment fire (Family Photo provided)

The woman was taken to a hospital with burns and was expected to survive, according to police and fire officials.

The fire has been ruled an arson, Gary Fire Department spokesman Mark Jones said Monday afternoon.

The Lake County Metro Homicide Unit and the Indiana State Fire Marshal are among the agencies investigating the fire, according to police and the coroner’s office.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2016. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)