Prosecutors say a southern New Jersey couple was killed when a fire broke out in their apartment.

Rolfo Rolf Brenner, Getty Images

Autopsies performed by the Burlington County Medical Examiner's Office determined that 66-year-old Katherine Jernegan and 63-year-old Joseph Coppola died from smoke and soot inhalation. Their deaths were ruled accidental.

Authorities were called to the couple's Bordentown City apartment just before 3 p.m. Sunday by a relative who had gone there for a visit and found them dead. Investigators say the fire was contained to the couple's unit and extinguished itself rather than spreading throughout the building.

It's still not clear what caused the blaze, but authorities said Monday that it's not considered suspicious.

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