BRONX, New York (PIX11)– The Bronx four-alarm fire that claimed a grandma’s life Tuesday has been ruled an accident, officials said Wednesday.

Investigators said the fire on Valentine Avenue in Tremont was caused by the “careless discard of smoking materials” and the smoke alarm was not working, fire officials said.

The fire devastated neighborhood residents still recovering from a fire one block over that left 17 dead earlier in the year. Flames broke out in a two-story residential building at Valentine Avenue and East 181st Street in Tremont at around 9:05 a.m. Tuesday, according to the FDNY. The fire then spread to two adjoining houses, police said. A video from the scene showed heavy flames and thick black smoke coming from the top of the building.

The residential building sustained significant damage to the roof and both floors, and six nearby buildings were also damaged, according to the Department of Buildings.

A 72-year-old grandmother was pronounced dead at the scene. Six firefighters and two civilians suffered minor injuries, officials said. Thirty-nine units and 168 firefighters brought the fire under control by 10:30 a.m.

The woman’s grandson was home during the fire, he said. The man, who identified himself only as Kareem, said he looked for people to help, but it was too hot and he needed to get out for his own safety. He could hear his mother screaming in panic during the fire.