PONTIAC, Mich. — A fire, which officials believe began when a window air conditioner, plugged into a strip outlet, overheated and caught the nearby carpet and couch on fire, killed a mother and her five children in Pontiac, Mich., north of Detroit.

Pontiac fire officials said that the rental home had no smoke detectors and did not have an occupancy permit, based on a number of code violations. Officials are pursuing criminal charges against the landlord in connection with the fire.

The dead include: Guillermina Carrasco, 26 and her children Grecia, 7, twins Enrique and Eduardo, 4, Veronica, 2, and Selena, 1. Carrasco was pregnant with twins.