Two football players at Lackawanna Junior College were injured during the same tackling drill in 2010. They sued the college in 2012, claiming the football staff was negligent and the school should have had certified athletic trainers available to aid and advise players who were injured. Instead, the college employed two women who had failed to gain certification as athletic trainers.
The claims were dismissed by the trial court on the ground the players had signed a waiver. The Superior Court reinstated the suits and now the Pennsylvania Supreme Court has affirmed that ruling. The court noted waivers against gross negligence and recklessness were ineffective and held there were sufficient facts for the players to present the case to a jury.
You can read more (although there isn't much) about the case here.