An open natural gas line was the cause of the explosion in Plantation that injured more than 22 people and decimated part of a shopping center, according to investigators.
The explosion hurled large pieces of concrete up to 50 yards away and sent pieces of metal scattering as far as 100 yards across the street as it destroyed a vacant pizza restaurant and left other businesses damaged.
The restaurant, called PizzaFire, had been out of business for several months.
The investigators concluded that either the valve at the behind the restaurant or in the customer area was turned – for reasons not yet known – on the day of the explosion shortly after 7 a.m.
Florida's Bureau of Fire, Arson, and Explosives Investigations released an Origin and Cause Report on the July 6 incident on Friday in which it said the ignition source of the explosion was likely from a heating, ventilation and air conditioning unit at the vacant business.
"The incident was caused by an explosion of natural gas being delivered in to the building by the permitted piping for the prir business tenant PizzaFire," the report reads. "The ignition source was likely electrical from an HVAC unit that was being utilized in the vacant business."
Numerous people who said they are victims of the explosion plan to file a lawsuit.