A West Oak Lane house fire Saturday morning killed two people and left a teenager hospitalized, authorities said.

When firefighters arrived at the two-story house on the 6700 block of North 17th Street, they saw heavy fire on the first floor, said Kathy Matheson, a spokesperson for the Philadelphia Fire Department. They worked from roughly 4:35 to 5:11 a.m. to get the blaze under control. Around 60 first responders were at the scene, Matheson said in an email.

A 64-year-old woman was found dead in the home, police said, and a 74-year-old man was taken to Temple University Hospital, where he was pronounced dead at 5:39 a.m. A 17-year-old female was taken to Einstein Medical Center Philadelphia, where she was in critical condition Saturday afternoon, police said.

The cause of the fire was under investigation.

“A heartbreaking morning in West Oak Lane, despite incredible firefighting, rescue efforts and EMS care,” the Fire Department tweeted Saturday morning. “Please keep the community and our members in your thoughts.”