Officials say a fire that broke out inside a Homecrest apartment building Monday night is being investigated as an arson.

Fire officials say the fire started just after 5:30 p.m. on the second floor of a six-story building on East 13th St. Crews were able to get the flames under control in less than an hour.

Officials say two people were taken to the hospital. One person remains in critical condition, while the other has injuries that are not considered life-threatening.

Now, a police source tells News 12 the fire is being investigated as arson, meaning investigators believe it was intentionally set. That determination was made by a fire marshal, according to the source. The case is now being treated as a serious felony investigation as authorities work to find who may be responsible.

As a result of the fire, a partial vacate order has been issued for the building. That means some residents are still not allowed back inside because of safety concerns.

Neighbors described frightening moments as people tried to escape.

“It’s very bad… I never saw people fall from a window. It’s scary,” said Yelena, who lives nearby.

Tenants say the situation inside quickly turned chaotic as smoke filled the building.

“After dropping off my son, I came back and smelled smoke,” said Kristina, a tenant in the building. “I had to run out to the fire escape because I couldn’t go down the stairs. It was terrifying.”

Kristina says the experience has left her shaken.

“I’m afraid to be with my son here… thank God this wasn’t happening while he was here,” she said.

The American Red Cross says it is helping three households, six adults total, with emergency assistance, including temporary housing.