Usmagazine.com has exclusive, never-before-seen footage of Michael Jackson‘s Pepsi commercial accident, filmed in L.A.’s Shrine Auditorium on Jan. 27, 1984.  The clip (watch below) shows one take where the pyrotechnics exploded as planned — after Jackson descended the stairs and began performing with his brothers. On the sixth take, though, things went horribly wrong:   The fireworks erupted too early, igniting Jackson’s head in flames. Jackson is at first unaware he’s on fire, and continues dancing.  He was never the same after the accident, reports the new issue of Us Weekly, on stands today. The accident is being called “How Michael Jackson’s Pill Addiction Began.”

To relieve the second and third-degree burns on his scalp and body (and later to help him tolerate multiple surgeries on the scorched spot on his head), Jackson was prescribed several medications — which kicked off his addiction to painkillers and obsession with plastic surgery, multiple sources tell Us.