I think the thread title says it all. The ambulance and paramedics were on the scene when I went past, and I really hope he's ok.
Sadly, he wasn't. http://www.thisisbristol.co.uk/news/Bristol-runner-dies-collapse/article-1082830-detail/article.html
By all accounts a remarkable guy who continued to run marathons after a quadruple bypass and had always said that if he died running then he'd die happy. RIP.