ARLINGTON -- Fire officials say an apartment fire that injured four people was intentionally set after a domestic dispute.

Crews were called to the Park Lane Apartments at 1523 Running Brook Drive Monday morning, according to Chief Tommy Gray with the Arlington Fire Department.

Eight apartment units were affected and have smoke and water damage, Gray says.

Most of the damage was inside an upstairs unit. Four people inside were taken to the hospital. One of them, a 25-year-old man with burns to 90 percent of his body, was then flown to Parkland Memorial Hospital, Gray said.

Officials say an argument began inside that unit, and the suspect left and came back with gasoline. He was one of the injured.

The fire is out, and crews are working to put out hot spots.

The investigation is ongoing, but AFD has labeled it as "criminal."