LAWRENCE, Mass. (AP) — Police and relatives have identified the two young boys killed in a four-alarm fire at a Massachusetts apartment building

Nine-year-old Kelvin Medina and his 4-year-old brother, Giancarlo Marrero, were trapped in a third-floor bedroom, after the fire broke out in Lawrence just after 3 a.m. Tuesday.

The state fire marshal determined that the blaze was an accident caused by an electrical wiring failure in a first-floor ceiling in the three-story, six-unit apartment building. Several cars were also destroyed by the fire.

Autopsies are scheduled on the boys’ bodies.

Residents who escaped said they were alerted by smoke alarms and a stranger who threw rocks at windows to alert residents.

Fire Marshall Stephen Coan says 48 people have died in fires in Massachusetts this year.

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