09/23/2008 at 05:00 PM EDT
Though Travis Barker is mourning the loss of two close friends and suffering from severe burns after surviving a plane crash
with DJ AM on Friday, a friend says the musician is trying to keep a positive outlook.
"If you make it out of a crash of that magnitude, somebody's looking out for you," says Bill Nosal, a friend who also acts as a spokesman for Famous Stars and Straps, a Los Angeles-based clothing and accessory line created by Barker. "He's trying to stay upbeat."
Four people were killed when the Learjet Barker and DJ AM were riding in crashed at the main airport in Columbia, S.C., including the pilot and co-pilot. Chris Baker, 29, of Studio City, Calif.; and Charles Still, 25, of Los Angeles, close friends of the musicians, died on impact. Nosal told the AP that Baker "was like extended family," to Barker.
There has been an outpouring of condolences and get-well messages for the victims of the crash. LL Cool J, who performed alongside DJ AM and Barker at the Video Music Awards earlier this month, told PEOPLE Tuesday: "Definitely my condolences to the families of the people who lost their lives. I hope that Travis and DJ AM have a speedy recovery and get back out there performing and creating for people. They're talented."
The two survivors managed to escape the wreck by "sliding down the wing on the right side of the plane," Lieut. Josh Shumpert of the South Congaree Police Department tells PEOPLE
Additional reporting by JENNIFER GARCIA