Prince's Sporting Club in Surrey has pleaded guilty at Southwark Crown Court to corporate manslaughter after 11-year-old Mari-Simon Cronje died when she was hit by a boat towing the inflatable she was riding.
Company director Frederick Glen Walker was cleared of any offences after the Crown Prosecution Service dropped charges against him.
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Metropolitan Police officer, Tom Harrison, has been crawling the course since the race began on Sunday morning.
The Old Bailey heard how Syed tried to get weapons online, including a bomb vest, and trawled the web to find a busy area launch an attack.
Hours after completing Sunday's course some of the runners put their medals on auction site eBay, with one attracting bids of almost £92.