But when the crew from Telford Central got to Oakengates Leisure Centre, in New Road, just after 2.44pm on Tuesday, they found they had got themselves out.
A spokesman for Shropshire Fire & Rescue Service said: "Fire control received a call reporting an incident classified as non-urgent in Oakengates Leisure Centre, New Road, Telford."
The spokesman added that the call was to "people locked in toilets who self-extricated prior to arrival of fire crew."
The crew's stand down message was sent at 3.05pm.
