And, after a traumatic day, somehow the show looks set to go on, with Saturday night’s performance of Bully Virus moved to the nearby Kathleen Syme Library and Community Centre. Members of Melbourne's performing arts community gathered in Faraday Street to mourn the loss of the iconic theatre. Artistic director Liz Jones has vowed the show will go on for La Mama. Credit:Meredith O'Shea Raymond Triggs was one of several performers to head to the scene on Saturday morning. "It's like a good friend has died," the part-time actor and builder said.

"I've been performing here for over 40 years and done a lot of building work on it in between, trying to keep the place going." Mr Triggs said he had built many of the additions to the theatre during its 50-year history, including the stairs, the box office, the brick paving, fence and gate. "Most of what's still standing," he said. The La Mama Theatre after the blaze gutted the Carlton building. Credit:Meredith O'Shea

Tributes poured in from across the country, including from leading lights in Australian theatre. Playwright David Williamson said he owed his career to the "national institution". Now one of the country's most celebrated dramatists, Mr Williamson said he was "eternally grateful" to founder Betty Burstall and the many talented actors who helped bring his plays to prominence. "I wouldn't have had a career as a playwright without La Mama," he said. Mr Williamson said La Mama launched the careers of a new generation of writers and actors.

The Carlton theatre was the epicentre of a revolution in Australian theatre, he said, at a time when it was dominated by English and US influences. "Major theatres regarded their role, to some extent ... to educate and uplift the barbarous natives into the higher points of European culture," he said. "Suddenly Betty came along and gave Australian actors the opportunity to do their own accents on stage and for writers to tell their own stories." Actor Damian Walshe-Howling, known for his roles in Australian TV shows Underbelly and Blue Heelers, said he also owed his career to La Mama. "Mum has been doing theatre there since 1969. Dad was working, it was the '70s and we didn't have any money for a babysitter," he said.

"Me and my brother spent so much time growing up there; La Mama was my babysitter." He said peering up from under rostrums and stairwells at the "magical landscapes" on the stage instilled in him his love of theatre, while "mucking around" with the actors taught him about playing characters. More than 50 firefighters took about 40 minutes to bring the fire at La Mama theatre under control. Credit:Metropolitan Fire Brigade Long-serving artistic director Liz Jones rushed to the scene after being called by police at 6.30am. "It's gutted and I'm gutted," she said.

"I feel like I'm in a nightmare." She said that, in a way, La Mama was like a person to her and those who had known it over the years. "I'm just devastated because the building had its magic, it wove theatre magic," she said. "It was a kind of rallying point really for the grassroots creative community of this state, of this country.

"And that's because it's just such an iconic space, such a spiritual space, such a very humble and modest space – but so much history has happened in there over the last 50 years." And Ms Jones was there for most of it. Loading "I've been working here since 1973 and I've been artistic director since 1976," she said. But Ms Jones said she had already been overwhelmed by support and had fielded calls from state government arts agency Creative Victoria as well as artists around the country.

"The feeling is that we must rebuild and we must go on," she said. "But somehow there has to be a future and it has to be a really good future and a wonderful and optimistic future, because it has been such an optimistic and positive place. "There is a future, we will go on." Ms Jones said she was encouraged after receiving a call from Creative Industries Minister Martin Foley and speaking with insurance assessors who had indicated that it would be preferable and might be possible to restore the existing structure. The building was constructed as a printing works in 1883 and is heritage-listed for its "historical, social and architectural significance to the state of Victoria".

But MFB acting assistant chief fire officer Mark Carter said, as of 10.15am, the building was “really quite dangerous inside” and the threat of collapse remained. Because of that danger, firefighters had rigged an alarm system to warn structural engineers and insurance assessors on-site if the walls moved. Several businesses on nearby Lygon Street were also closed. “We've had serious structural collapse on the inside of the building, the roof's gone, the upper level floor's gone and at the moment we've got a pile of burning rubble,” Mr Carter said. He said fire investigators were working with Victoria Police to determine the cause of the fire, a process which could take days.

CCTV and drone footage, and testimony from witnesses and first responders will be compiled as evidence over coming days. La Mama celebrated its 50th birthday last year which it celebrated with a "mini-fest" which included a David Williamson play which was "too controversial" for the mainstream. Mr Williamson said his relationship with the theatre began at its inaugural meeting in 1967, at which he was a "somewhat intimidated" university reviewer among some of the leading writers of the day. Soon after La Mama staged his first plays, including The Removalists, which launched his career. It was on the cobble-stone streets in front of La Mama where where he met his wife of 47 years.

If that was his most "stunning memory", there were others he said he would like to forget. "Such as the evening a gentleman defecated in a toilet bowl on-stage," he said. "I'm not sure what he was trying to prove ... but it certainly was malodorous." But that was the beauty of La Mama, Mr Williamson said. If someone could provide "plausible evidence of talent" they got their chance to take to the stage. That made it both an important "learning ground" for young talent and an exciting spectacle for those willing to take a risk.