The Fire Marshal’s Office is investigating a Southwest Center City rowhouse fire that claimed at least one life Saturday.

The Philadelphia Fire Department responded to the 2200 block of Catharine Street around 5:30 a.m. to discover fire on the first floor of the building, with smoke visible from the second floor.

Rescuers found one occupant, who was given emergency medical care and transported to a hospital, a spokesperson for the department said, declining to provide additional details.

The fire was contained within two minutes. Investigators are looking into both its cause and origin.

“A tough morning for the community and for our members who responded to this fire in SW Center City,” the Philadelphia Fire Department said in a tweet this afternoon. “Our thoughts are with all those affected.”