A Good Story in case you have not heard it:

[clydepepper]

Tom Walker pitched in the majors from 1972 through 1977 and is the father of Pittsburgh Pirates second-baseman Neil Walker.

After his rookie season in 1972, Walker decided to play winter ball in Puerto Rico, along with Expos pitcher Balor Moore and some members of the Pittsburgh Pirates. Roberto Clemente was their manager. Walker felt fate entered his life when on December 31 Clemente planned to fly in a plane carrying supplies to earthquake victims in Nicaragua. Clemente told Walker and the other players to stay behind and enjoy New Year’s Eve in Puerto Rico.

That night Clemente’s plane burst into flames shortly after take-off and plunged into the dark waters. Walker said he would forever remember that day and how the island was devastated. Clemente’s fellow Puerto Ricans revered him. Out of respect for their fallen hero, the league canceled the balance of the season.

“I can still remember it like yesterday,” Walker said. “We left the airport and it was the last time I ever saw Roberto Clemente. He saved my life by not letting me get on the plane.”

Roberto Clemente gave his life in an attempt to help others and I don't know any other star athlete who has done so.