No suspicious circumstances in Olympic site fire

LONDON (Reuters) - A huge blaze in an empty warehouse on 2012 Olympic Park last week was started when an oxy-acetylene torch ignited insulating material, the Olympic Delivery Authority (ODA) said on Wednesday.

Black smoke billowed across the city last Monday, briefly sparking security fears. The ODA has ruled out any suspicious circumstances.

It said a contractor sparked the fire when cutting through steel piping during demolition of the warehouse and that "hot working" on similar buildings had been temporarily suspended pending a review of procedures.

"These findings confirm initial indications both that the fire was caused by accident while the warehouse was prepared for demolition and that public health was not put at risk," ODA chief executive David Higgins said.

The ODA also said monitoring equipment had not detected asbestos in the air around the building during and after the fire, or in dust and debris from the smoke plume.

Demolition work, decontamination and earthworks are in progress on the 2.5-square kilometre (620-acre) site which will host the Olympic Stadium and other main venues. Construction is scheduled to start next year.

(Reporting by Martyn Herman; Editing by Robert Woodward)