"Goetz has always been ahead of her time, finding artists no one else has ever heard of, " says Christie's Mr. Outred.

WSJ: Collecting: Bacon, Richter and Basquiat to Headline Contemporary Art London Sales

Alastair McKenzie, who works at Anthony Outred Antiques, said he was in their shop next door and heard the first explosion, minutes before seeing the fireball emerge from the pavement.

BBC: Pimlico pavement explodes, narrowly missing passer by