PITTSFIELD — A fire that killed a city woman and injured a firefighter last week was caused by the improper discarding of smoking materials, officials said Tuesday.

Firefighters rescued Frances Lysonski, 74, on July 6 from her home at 73 Chickering St. Lysonski was taken to Berkshire Medical Center, where she died from her injuries.

The fire began in a plastic trash barrel on the first floor of the home, according to the state Department of Fire Services. Authorities found several packs of cigarettes and matches near where the fire originated.

The blaze was investigated by the Pittsfield Police and Fire departments, the Berkshire District Attorney's Office and the state Fire Marshal.

Authorities said the residence had no working fire alarm. The home's two alarms were well past their suitable replacement age and had dead batteries. Also, one of them was obstructed by a number of boxes.

Massachusetts Fire Marshal Peter Ostroskey said the state has seen three fatal fires this year in which smoke alarms have been expired. Smoke alarms come with an expiration date on the side and should be replaced every 10 years, he said.

"Working smoke alarms give you early warning of danger, and in a fire, you need every second," Pittsfield Fire Chief Tom Sammons said. "Expired alarms cannot be relied on to work you when you need them most."