DADE CITY, Fla. — Investigators have determined the cause of a Friday fire that heavily damaged the Dade City Business Center.

Pasco County Fire Rescue Fire said Tuesday the cause was welding by an employee.

The fire started at about 12:30 p.m. Friday in the 15200 block of Citrus County Drive in Dade City. It took about 18 hours for crews to get the blaze under control.

"During preventative maintenance, employees were in the process of extending an exhaust duct to an industrial rotary furnace when sparks from the welder ignited combustibles in the area," Pasco County Fire Rescue said in a news release.

"Employees made several attempts to extinguish the fire before calling 911 and evacuating the building."

The fire caused about $3 million worth of damage to the center.

No injuries were reported.