Cause of Gilbert construction site fire deemed accidental

Investigators have determined that the cause of a massive five-alarm fire at a Gilbert construction site is accidental.

The Gilbert Fire Department tells Fox 10 that following an investigation assisted by the ATF, the cause of the fire is accidental.

On April 23, more than 100 firefighters from different agencies responded to the massive fire at a construction site near Gilbert Road and Arizona Avenue.

Nearby residents were evacuated from the area and one firefighter and three police officers suffered minor injuries.

Investigators say the only know heat source at the construction site was a torch that was used by roofers.