Life as a musical superstar isn't all just fun and glamour. Despite the lavish existence most famous musicians lead, at the end of the day ... they're just people, too. And like most goodhearted folk, when tragedy strikes, many celebrities spring into action to help save the day. For some stars, that means donating money to a charity in need, or endorsing a good cause. But for others, being a do-gooder is more of a hands-on job. Read on for the most harrowing tales of celebrity heroism -- from the singer who saved two children from a raging fire, to the rapper who talked a suicidal man off a building's ledge!