At least 13 people, including seven children, were killed in an early morning fire on Wednesday in a Philadelphia house after smoke detectors failed to go off, the Philadelphia Fire Department said.

Firefighters arrived around 6:40am (1140 GMT) and fought for about 50 minutes to control the fire on the second floor of the three-storey house in the city’s Fairmount neighborhood. Eight people managed to escape the building, and seven children were among those killed, fire officials said. They did not give the children’s ages.

A child and an adult were taken by parademics to nearby hospitals. There were four smoke detectors in the building, which is owned by the city’s public housing authority, but they failed to activate, fire officials said.