Firefighters feared a security guard could have been killed when a council office ceiling collapsed in Horsham.

The suspended ceiling in the reception of Horsham District Council in North Street caved in at 1am today, causing major damage.

Firefighters searched with thermal imaging cameras fearing the security guard was trapped in the debris. However, after an hour they discovered the man had gone home.

A witness said: "If it had happened during the day someone could have been killed. It looked like the whole ceiling had just fallen away. It was quite spectacular.

"No one seems to know why it happened."

Cable experts, working on the council's computer systems 24 hours a day, called 999.

A council spokesman said: "We've had teams clearing away the rubble through the night.

"The area is now clear and the council is open and running as usual, though we will have to put the ceiling back in place.

"We don't know why it happened but it is being investigated."