The December death of a Massachusetts firefighter has been ruled a homicide after authorities determined the blaze he was fighting in an apartment building had been deliberately set by a tenant.

Worcester (WUH'-stur) firefighter Christopher Roy was a single father who is survived by his 9-year-old daughter. He died Dec. 9 after he became trapped on the second floor of the six-unit building. He was rescued by fellow firefighters and died at the hospital. The cause of death was smoke inhalation.

Worcester District Attorney Joseph Early Jr. announced Friday that a former tenant, 21-year-old Momoh Kamara, had been indicted on second-degree murder, arson and burglary charges.

Kamara now lives in West Boylston. He is scheduled for arraignment later Friday. It's not clear if he has a lawyer who could comment.