I think the blade hit a rock.
Seriously though, it was a pulling tractor that over revved from the excess fuel left after a run... http://forums.24hoursoflemons.com/viewtopic.php?id=15927
Seriously though, it was a pulling tractor that over revved from the excess fuel left after a run... http://forums.24hoursoflemons.com/viewtopic.php?id=15927