Firefighters responded to an emergency at one of Apple’s facilities in Mesa, Arizona on Tuesday afternoon after a blaze broke out in an area of solar panels fitted to the roof of the building.

According to local news reports, firefighters identified that the fire erupting on the 12-hecatare site was located only on a section of the roof overlooking a loading dock.

While around 50 people were forced to evacuate the building, over 100 firefighters were able to get the blaze under control in about 30 minutes, although a portion of the roof collapsed.

News reports noted that fire investigators are trying to find out if the fire was a direct result of the solar panels located upon the roof.

The facility features a lengthy history. First Solar was the original owner of the building, eventually selling it to Apple in 2012. Apple then leased it to GT Advanced Technologies (GTAT) in order to use the space as a factory to manufacture sapphire screens for handheld devices.

Ultimately, the sapphire-screen factory plans never came to fruition, as GTAT eventually filed for bankruptcy last year. As a result, Apple shifted the building’s purpose into that of a data centre, touting its green credentials.