Emergency services were called to Brean Sands Holiday Park in Somerset at about 6.30pm on Wednesday (February 20) evening.
Devon and Somerset Fire and Rescue Service said officers responded to reports a "section of ducting collapsed into the bar area of a building" at the holiday park.
About 100 people were thought to have been in the building at the time.
A 40-metre section of ducting and ceiling fell, exposing live electrical cables.
Fire crews used air bags to establish no-one was trapped underneath the debris.
The incident means the main clubhouse entertainment area will be out of use for some time.
