The singer – who said he was just 10 years old when his father died of lung cancer – movingly told the audience, “One day, we hopefully won’t need to have events like this.”
Roberts started the night off by introducing her good pal and his band to the raucous New York fans: “I cannot tell you how excited I am to be in the greatest city in the world to introduce one of the greatest bands of the world!”
As the crowd roared, she thanked everyone who came to the concert. “We should all feel good about participating,” she said. “I’m thrilled to be able to say that on September 10 that we are welcoming some of the heroes and first responders from September 11. As New Yorkers, we are beholden to all of them.”
A whole host of celebs came out to support the charity event, including Mary-Kate Olsen, Gossip Girl‘s Chace Crawford and Lindsay Lohan (who got to the Garden at 6 p.m. to watch girlfriend Samantha Ronson DJ for the pre-party).
• 2005: Julia stars in Dave Matthews Band video!
• Get your fix of the Pretty Woman! See ALL of her PEOPLE covers!
• See stars who’ve bravely battled cancer on the covers of PEOPLE