Boy Scout accident
Although the Boy Scouts teaches its members how to make ethical and moral choices in life, they also place a heavy emphasis on safety. And even though the members are just children, some of them can smell danger a mile away, or at least 10 to 15 meters high.
While out on a scouting trip, the OP and his peers wanted to go “bouldering,” which is apparently an activity where you climb up tall boulders without safety gear. After seeing how high they were going to climb, OP opted out of it and walked away. An hour later, one of the guys who went bouldering fell down and cracked his skull open.