UPDATED | July 31, 2017 8:57 AM

ARLINGTON (CBSDFW.COM) – Police say a domestic argument and subsequent two-alarm fire at an apartment complex in Arlington has left at least four people injured.

Calls about the fire at the Runningbrook Apartments, near Park Row Drive, started coming in around 6:30 a.m. When first-responders arrived they found heavy flames and smoke shooting from the roof of at least one of the units.

Arlington investigators say everything started with a domestic argument/fight and a male suspect left the complex and came back with gasoline. At some point later a fire was set in the apartment and all of the people inside, including the suspect, were injured.

Carol Lee lives at the complex. She said, “When I walked out I seen [sic] a boy sitting on the side of the thing and his arms were burnt… looked burnt.”

Apartment resident Lee Howard said the first thing she heard was a loud bang. “The next thing we know we come to the front door and we seen [sic] a guy rolling down the stairs on fire. Next thing we could tell everybody was saying, ‘Get out! Fire!’”

One of the injured reportedly has burns over 90-percent of their body. That victim was taken to Medical City of Arlington and then transported by air ambulance to the burn unit at Parkland Memorial Hospital.

Investigators are still trying to figure out the events that lead up to the fire being set. Police say the incident is being filed as a criminal investigation.

* This is a developing story and will be updated as more information becomes available.