(AP) - Federal investigators say a malfunctioning power strip sparked a New Jersey house fire that killed five children.

The report from the Bureau of Alcohol, Tobacco, Firearms and Explosives also concludes the July 13 fire in Union City was an accident.

The report made public Thursday by Hudson County prosecutors states the power strip started sparking after an electrical failure, which ignited nearby flammable materials in a first-floor apartment at the home.

The children - 2-year-old Jason Gonzalez, 4-year-old Shamira Lopez, 5-year-old Mayli Wood, 7-year-old Christian Josue Mendez and 13-year-old Jose Felipe Tejada - died from injuries suffered in the fire. They were all asleep in a third-floor apartment when the fire broke out.

Officials have said four of the children were siblings, while the fifth was a relative. A man and a woman were also injured in the fire.