A thrift store in Lewisville was destroyed in a fire early Wednesday morning.

The fire was reported just before 6 a.m. at Thrift World, which is located at a strip mall in the 1300 block of West Main Street.

The Lewisville Fire Department says by the time firefighters arrived, the building was already engulfed in large flames and heavy smoke.

A large portion of the roof had also collapsed, forcing crews to go defensive and battle the fire from the outside only.

Fire started at thrift store

The fire went to four alarms, which meant additional trucks and manpower could be brought in. At one point, there were 100 firefighers from six different agencies on the ground.

"There's a lot of functions have to be done on a fire, even when you're just squriting water on the outside," said Lewisville FD Assistant Chief Mark McNeal. "There's a lot of hoses, a lot of tools, a lot of forcible entry. So we just need the manpower. The initial crews get tired really fast and we have to swap them out."

Because all of the stores in the shopping center were closed when the fire broke out, no one was inside the building at the time.

Fire officials said there were no reports of any injuries.

The cause of the fire is under investigation.

NBC 5's Tim Ciesco contributed to this report.