Published Thursday, 19 December 2013
Police have cordoned off the area. (© PA)
The incident happened at around 8pm on Thursday evening during a performance of The Curious Incident of the Dog in the Night-time at the venue at Shaftesbury Avenue in the West End.
The London Fire Brigade said the theatre was almost full, with "around 700 people" watching the performance.
Eight fire engines were sent to help with the rescue mission and a team of firefighters rushed through the front stage door.
Metropolitan police initially confirmed there were more than 40 walking wounded being treated and a London bus was used to transport some of those more seriously injured to hospital.
The London Ambulance service later confirmed more than 88 people had been injured.
"We have sent a large number of staff to the scene, including 25 ambulance crews, 12 officers, members of our hazardous area response team and a medical team from London's Air Ambulance also attended in a car," a spokesperson said.
"We have been working closely with the other emergency services to treat the injured."
Eyewitnesses said they saw people being escorted out of the building, covered in dust and debris and some who were evacuated were bleeding.
Police were on the scene within minutes and began cordoning off the theatre.
One theatre-goer, Khalil Anjarwalla who was there with his heavily pregnant wife and her parents managed to escape from the theatre safely after "kilos of concrete plummeted from the ceiling".
"I was in the upper circle with my family when, about 45 minutes in, people started shouting and screaming," he said.
"We thought it was part of the play. But the ceiling was crumbling. Within an instant the whole roof seemed to come down.
"We saw a lot of people completely covered in dust - I could hardly breathe."
He added: "Thankfully we are all OK. My wife is seven months pregnant but she is OK. We feel very blessed."
© UTV News