"...when the fire alarm went off. The band carried on playing, and eventually the MC wandered on stage..."

That's appalling.

If a fire officer had been present at that time, the whole place would have been closed down. The band should have been stopped and the MC should have interrupted them if they continued. Those premises should have been evacuated regardless of what the MC thought it was... if he'd been wrong and it was the PA equipment or a stray barbeque or an irresponsible smoker.... the consequences could have been catastrophic.

But first and foremost - someone should have checked out the bands' stage act to make sure it didn't start off the fire alarms or the sprinkler system.

LTS