PHILADELPHIA (AP) — Fire investigators are seeking the cause of an early morning blaze that tore through a six-story apartment building in Philadelphia's Old City.

Authorities say scores of people, including guests of a hotel, were evacuated after the alarm was sounded shortly after 3 a.m. Sunday.

Fire crews were reported the building engulfed in flames, and flames were still visible more than five hours later. The blaze was declared under control at 7 a.m. Sunday.

Deputy director Noelle Foizen of the Office of Emergency Management told The Philadelphia Inquirer that everyone had been accounted for. She said about 75 people took shelter at the Museum of the American Revolution across the street.