Brendan Bialy, the aspiring Marine who jumped into action during the Colorado school shooting, said he desperately pumped the chest of his fallen friend after they tackled one of the attackers. Despite his efforts, 18-year-old Kendrick Castillo died after throwing himself on the shooter at STEM School Highlands Ranch on Tuesday. Another heroic student, Joshua Jones, suffered two gunshot wounds during the scuffle and is recovering at home.