ST. PETERSBURG, FL — Investigators determined the cause of an early Sunday morning house fire on Coquina Key was arson, St. Petersburg police said in a news release.

St. Petersburg Fire Rescue responded to the fire in the 3900 block of Neptune Drive SE around 3:30 a.m.

The fire left 18-year-old Angelina Anderson dead and a 35-year-old woman hospitalized in critical, but stable, condition, police said.

A teenager and a younger child at the home during the blaze were treated in the hospital for smoke inhalation and released.

Investigators are asking that anyone with information about a suspicious person or unusual activity in the area around the time of the fire’s start at 3:18 a.m. contact police at 727-893-7780.

Detectives are also interested in any video recordings or other information the public may have.

Tips can be shared by texting the information and “SPPD” to TIP411.