AHWATUKEE, Ariz. (AP) — Three people have been found dead after an apartment fire early Monday in the Phoenix suburb of Ahwatukee, authorities said.

Phoenix Fire Department Captain Todd Keller said crews responded to the blaze around 6:45 a.m. and located three adults inside a second-floor bedroom of the three-level apartment complex.

“Unfortunately the individuals were beyond resuscitation,” Keller said.

Authorities say the victims — believed to be two women and one man — weren’t immediately identified.

Keller said the department’s Fire Investigations Task Force and Phoenix Police are trying to determine the cause of the deadly blaze.

Ahwatukee is about 13 miles (20 kilometers) southeast of Phoenix.