Watch: This Morning chaos as alarm bells end Mel B interview
The Spice Girl was on the ITV morning show to talk about Trailblazers: A Rocky Mountain Road Trip, the road trip programme that she is making with comedian Ruby Wax and TV star Emily Atack.
But she had barely got started when an alarm started to blare around the studio.
The presenters made it clear to the star and to viewers that there wasn't a fire and that it was a false alarm.
However, Mel was clearly in her stride and, plopping herself on the sofa in between the hosts, she started reading off the autocue and raced through their announcements for them as they giggled.
O'Leary said: “I told you she was a hurricane - she comes in and the fire alarm goes off!”
“I love when it goes wrong on live TV!" said Hammond.
"But we did a check and the building is not on fire.”
“I do too," Mel chimed in. "But you two are good at making it all seem really normal… you’re good!”
The show then cut to an ad break, before returning for Mel's chat.
Viewers thought the whole thing was hilarious.
"Fire alarm going off lol," posted one.
Another said: "Lmaooooo not the fire alarm going off on This Morning."
"All hell has broken loose and I love it, bring Mel B in permanently with these two amazing dream team," said somebody else.