Beloved La Mama theatre gutted by fire

Half a century of performing arts history has gone up in flames, after the La Mama theatre in Carlton was destroyed by fire.

The industry favourite has welcomed some famous names in the past, but may now be demolished after the blaze earlier this morning.

The theatre burst into flames at about 5am, with the blaze spreading quickly through the 400sq m site and causing the slate roof to collapse.

Up to 50 firefighters were called in to tackle the fire, with crews forced to deal with access issues through the morning.

"Little tight laneways are all great for pedestrian access, but when you are trying to get a big red truck in, it presents a lot of problems," Metropolitan Fire Brigade spokesman Mark Carter said.

The intense heat of the fire prompted concerns about the structural Integrity of the building, forcing police to cordon off the area over fears the wall might collapse onto neighbouring businesses.

As the sun rose, friends of the theatre arrived at the scene to see what remained of their beloved building.

"It just feels like a family coming together after someone has died, you know," venue manager Hayley Fox said.

"Visually it's just a shock, because it is so gutted," theatre director Laurence Strangio said.

It was only last year that La Mama celebrated 50 years of operation, previously welcoming Cate Blanchett, Julia Zemiro and David Williamson in that time.

The fire is not suspicious, although investigators are still trying to determine how it started.