Firefighters have gained the upper hand on a massive four-alarm blaze that destroyed a produce warehouse in Etobicoke early Friday morning.

Toronto Fire Services division commander Len Stadler said the blaze has been contained and crews are now controlling hot spots within the building.

“The fire was pretty aggressive. The crews had their hands full on arrival," Stadler told CP24 reporter Cam Woolley at the scene.

Fire Capt. David Eckerman said the blaze began in a truck parked in a loading dock around 2 a.m. and spread to the single-storey industrial building. The fire went into a fourth alarm shortly after fire crews arrived.

As the fire burned out of control, flames were shooting out of the roof, doors and windows of Wei Fung Fruit Co. at 99 Birmingham St., near Islington Avenue and Lake Shore Boulevard, and a huge wall of smoke drifted into the air.

When firefighters entered the building, flames were as high as 4.5 metres (15 feet) and the building was filled with heavy smoke, Eckerman told CP24.

The fire continued to spread into the attic and roof.

Firefighters had difficulty accessing the building because large vehicles belonging to the company were blocking overhead doors. A tow truck driver arrived and pulled the vehicles out of the way.

Because of the hazardous conditions and worsening situation, firefighters pulled out of the building for their own safety about an hour after they arrived and began battling the blaze in a defensive attack.

At one point, the building's roof collapsed.

One of the biggest concerns was protecting a neighbouring temple located just a few metres from the burning building.

To prevent the fire from spreading, at least two aerial ladders poured water on the inferno and several firefighters took positions on the temple's roof to spray water on the flames.

No injuries have been reported. No one was inside when fire crews arrived.

The Office of the Fire Marshal is investigating the cause of the blaze, which caused hundreds of thousands of dollars in damage.