Nearly 90 people injured when the ceiling of a theatre in London caved in during a performance Thursday night are being treated at area hospitals.

Medical staff were on hand at St. Thomas' Hospital to receive the wounded... most of whom suffered head injuries.

It happened at the Apollo Theatre in London's West End entertainment district during a packed performance of "The Curious Incident of the Dog in the Night-Time."

Officials said a 10 meter square section of ornate plaster ceiling fell onto the audience during the show.

Police say it's too early to tell what caused the ceiling to fall.