Fitzgerald said the cause of the fire was under investigation, but given its size and rapid spread initial indications pointed to the possibility of arson.
"It definitely is a suspicious fire we are looking at here," he said. "We're following up on leads, and trying to figure out which car went up first. ... We are fairly confident that one of these vehicles was intentionally set on fire."
Witnesses reported seeing an unfamiliar vehicle in the area shortly before the fire erupted, and Fitzgerald said that was one of the leads investigators were pursuing.
Fitzgerald said that in addition to heat and flames, this particular fire posed potential health risks to crews and residents due to the toxic nature of smoke from gasoline, plastics and electrical components as they burned.
One firefighter was treated at the scene for minor injuries after he slipped on ice and fell, but no one else was hurt, according to the West Valley City Fire Department.
Residents of two apartment buildings nearest to the flames had been initially evacuated, but were allowed to return within an hour.
Damage from the fire was estimated between $150,000 and $200,000.