As you may have already heard, DJ AM and former Blink 182 drummer Travis Barker were severely burned in a plane crash which killed four other people. According to CNN.com, they both suffered second and third degree burns, Barker to the torso and lower body, and DJ AM to the head and arm. They are currently at the Joseph Still Burn Center in Augusta, Georgia.
I've worked in a Burn Unit several times during my plastic surgery training, and now occasionally take care of minor burns. Third degree burns are also known as full thickness burns, and necessitate skin grafting for the area to properly heal. Second degree burns (split thickness burns) are characterized by blistering. Depending on how they heal, second degree burns may or may not need skin grafting. Burns wounds, as you may guess, are extremely painful and often require a lengthy recovery. I don't know their exact medical details, but it sounds to me that the burns they suffered are usually not fatal. Burns like what they reportedly have, though, usually require several weeks in the hospital and several months in physical therapy.
I wish these two guys the best during their recoveries.