On 5 September 1975 a bomb exploded in the lobby of the Hilton Hotel on Park Lane, London, killing two people and injuring 63.

Having been notified, Scotland Yard immediately sent three officers to investigate, but they were not able to evacuate the building before the bomb exploded at 12:18 BST.

The blast caused extensive damage to the hotel and neighbouring shops with broken glass spread over a wide area.

A spokesman for the Metropolitan Police said an officer telephoned the Hilton shortly after receiving the warning, but the hotel denied this.

"A policeman was just telling the assistant manager that he had better evacuate when the bomb went off," said press officer Anne Crewdson.