After last week's extraordinary episode, when a performance of this play was lost through the discovery of an unexploded Second World War bomb on the building site next to the theatre, Tuesday night's fire-alarm evacuation seemed a minor inconvenience.
It was even reassuring in a way, given that this show about the wartime bombing of Coventry contains some of the most dramatic pyrotechnics I've ever seen in a theatre.
Not surprisingly, intense local interest in the subject led to Alan Pollock's new play selling out before it opened, and neither the play nor its production sells the city short.
It would be even better without the last 10 minutes or so, when the attempt to resolve it becomes hamfisted and distractingly melodramatic, but for the most part the Belgrade has delivered the kind of quality you expect down the road in Stratford.
Pollock has ingeniously linked the ordinary Coventrian's perspective on the notorious raid of November 14 1940 with a strategic view of the war through a love affair between Katie, daughter of a shop-steward at British Thompson Houston's Coventry factory, and Michael, a young man she meets in the blackout on the platform of Henley-in-Arden station.
Michael, who is unable to reveal that he works at the code-breaking establishment at Bletchley Park, receives prior knowledge that the city is being targeted, but is unable to warn Katie's family.
Where the play and Hamish Glen's production score is that they set up strong and interesting characters that we really care about.
Katie is the bright working-class girl with plans to become a teacher, Michael the Oxford-educated, German-speaking son of Jewish jewellers in Birmingham, Katie's father the Communist shop steward who starts out with a cynical view of the "boss's war", her younger sister a bubbly streetwise kid. Performances are consistently good.
Making full allowance for theatrical licence, the play is remarkably successful in evoking the raid itself, providing more than enough trauma for the audience's imagination to feed on.
The play questions whether Churchill may have turned a blind eye to defending this particular raid because of its propaganda value, but a more fundamental question is surely why an industrial city so important to war production was not routinely better defended.
* Running time: Two hours, 30 minutes, Until March 29 (returns only).