"The crew reacted to a sound that was consistent with a tire blowout," Hersman said.
Former Blink-182 drummer Travis Barker and celebrity disc jockey DJ AM were critically injured in the crash, but one of their doctors said Sunday he expected them to fully recover.
Two of the musicians' close friends and two crew members were killed when the plane shot off the end of the runway, ripped through a fence and crossed a highway. It came to rest on an embankment a quarter-mile from the end of the runway, engulfed in flames.
Hersman said no cause of the crash has been determined and the investigation is ongoing. She did say that pieces of tire were recovered about 2,800 feet from where the plane started its takeoff. The runway is 8,600 feet long.
The plane was traveling at least 92 mph, its minimum takeoff speed, when the crew thought the tire burst, Hersman said.
The plane was headed for Van Nuys, Calif. It is owned by Global Exec Aviation, a California-based charter company, and was certified to operate last year, Hersman said.
Pilot Sarah Lemmon, 31, of Anaheim Hills, Calif., and co-pilot James Bland, 52, of Carlsbad, Calif., died in the crash. Also killed were Chris Baker, 29, of Studio City, Calif., and Charles Still, 25, of Los Angeles. Baker was an assistant to Barker and Still was a security guard for the musician.
The two musicians suffered second- and third-degree burns but had no other injuries from the crash, said Dr. Fred Mullins, medical director of the Joseph M. Still Burn Center in Augusta, Ga.
Barker was burned on his torso and lower body and DJ AM, whose real name is Adam Goldstein, was burned on an arm and a portion of his scalp, according to a statement from the musicians' families released by the hospital. Such injuries can take a year to fully heal, however, Mullins said he didn't think it would take that long.
Both men were in critical but stable condition, he said.
Several fans visited the hospital over the weekend. One carried a sign that read: "Get Well Travis."
"I was just shocked when I first heard it and I knew that I had to do something," said Ryan Meadows, a 19-year-old college student from Augusta.
Barker and Goldstein had performed a together under the name TRVSDJ-AM at a free concert in Columbia on Friday night. The show, which included performances by former Jane's Addiction singer Perry Farrell and singer Gavin DeGraw, drew about 10,000 people to a neighborhood near the University of South Carolina.
Barker, 32, was one of the more colorful members of the multiplatinum-selling punk rock band Blink-182, whose biggest album was 1999's CD "Enema of the State" and sold more than 5 million copies in the United States alone.
After Blink-182 disbanded in 2005, Barker went on to form the rock band (+44) -- pronounced "plus forty-four." He also starred in the MTV reality series "Meet the Barkers" with his then-wife, former Miss USA Shanna Moakler. The show documented the former couple's lavish wedding and home life. Their later split, reconciliation and subsequent break up made them tabloid favorites.
Goldstein, 35, is a popular DJ for hire who at one time was engaged to Nicole Richie and dated singer/actress Mandy Moore. While he became a gossip favorite for his romances, he draws respect from music aficionados for his DJ skills.
Barker and Goldstein performed as part of the house band at the MTV Video Music Awards earlier this month.
