23.11 Hrs News Update. London ambulance saying 81 walking wounded and seven more seriously wounded after part of ceiling fell in taking part of the upper balcony. "Fortunately all those who were trapped have been rescued and treated for injuries or taken to hospital," London Fire Brigade said.
2220: Lots of theatre stars are at the after party for the new Andrew Lloyd Webber musical nearby. Impresario Bill Kenwright said he was "shocked", while comedian Jimmy Carr said: "My heart goes out to everyone involved at the theatre".
Simon Usborne features writer at The Independent tweets: Back home after Apollo theatre collapse. Terrifying. Sheltered in stalls by upper circle. Loud bangs, cracks. Thought was part of show...
He added: ... then whole interior of theatre filled with curtain of dark grey dust and debris, falling on heads of anyone not sheltered....
2215: Police, rescue and emergency crews reached the Apollo Theatre within minutes of the collapse, eyewitnesses have told the BBC.
Eyewitness Khalil Anjarwalla, who was watching the performance with his heavily-pregnant wife, said he was "shocked" by the incident.
Ross Hawkins BBC political correspondent tweets from the scene: First response 3 mins after call, 85 casualties, taken to 3 hospitals
2211: Lucy Atherton was watching the show with her family.
Speaking to the BBC she said the theatre was packed when the roof crumbled.
2210: Specialist urban search and rescue crews were called to the scene who searched the theatre for people who might be trapped.