Two men have been rushed to hospital with serious injuries due to a fire on the roof of an industrial warehouse in Etobicoke.

The fire broke out in the warehouse in the area of Kipling Avenue and Rexdale Boulevard, according to Toronto Fire Services spokesperson Stephan Powell. The call was received shortly after 5 pm.

A caller reported hearing an explosion and seeing flames.

When firefighters arrived, they encountered a large black plume of smoke. The fire, which is now partly out, prompted people to leave the building.

Tow-truck operator Sonny Subra shot video of the scene and posted it on Twitter.

Industrial Fire Bethridge rd and Kipling Ave. So many <a href="https://twitter.com/Toronto_Fire?ref_src=twsrc%5Etfw">@Toronto_Fire</a> also so many ambulance on scene, <a href="https://twitter.com/TPSOperations?ref_src=twsrc%5Etfw">@TPSOperations</a> <a href="https://t.co/i20aFgUbHn">pic.twitter.com/i20aFgUbHn</a> —@SonnySubra

Toronto paramedics rushed the two men to hospital in separate emergency runs.

According to Toronto Fire, the men were reportedly working on the roof when the fire broke out, but firefighters haven't determined what they were doing.

There's no word yet on the cause of the fire, which is still under investigation.

Police said the Ontario ministry of labour will investigate the fire because the roof can be considered a workplace at the time of the blaze.