Friends, family, and teammates gathered at a private memorial service this afternoon to pay their respects to Minnesota Vikings offensive tackle Korey Stringer, who died of heatstroke Wednesday morning. The 335-pound player collapsed after practice on Tuesday. Questions continue to surround Stringer's death, including whether it could have been prevented, and if so, who's responsible. Matt Mitten, Director of the National Sports Law Institute at Marquette University in Milwaukee says this could be a situation where no one is liable: