Here is the part of Moon Walk were Michael talks about it:
"I had planned to spend most of 1984 working on some movie ideas I had, but those plans got sidetracked. First, in January, I was burned on the set of a Pepsi commercial I was shooting with my brothers.
The reason for the fire was stupidity, pure and simple. We were shooting at night and I was supposed to come down a staircase with magnesium flash bombs going off on either side of me and just behind me. It seemed so simple. I was to walk down the stairs and these bombs would blow up behind me. We did several takes that were wonderfully timed. The lightning effects from the bombs were great. Only later did I find out that these bombs were only two feet away from either side of my head, which was a total disregard of the safety regulations. I was supposed to stand in the middle of a magnesium explosion, two feet on either side.
Then Bob Giraldi, the director, came to me and said, "Michael, you're going down too early. We want to see you up there, up on the stairs. When the lights come on, we want to reveal that you're there, so wait ."
So I waited, the bombs went off on either side of my head, and the sparks set my hair on fire. I was dancing down this ramp and turning around, spinning, not knowing I was on fire. Suddenly I felt my hands reflexively going to my head in an attempt to smother the flames. I fell down and just tried to shake the flames out. Jermaine turned around and saw me on the ground, just after the explosions had gone off, and he thought I had been shot by someone in the crowd - because we were shooting in front of a big audience. That's what it looked like to him.
Miko Brando, who works for me, was the first person to reach me. After that, it was chaos. It was crazy. No film could properly capture the drama of what went on that night. The crowd was screaming. Someone shouted, "Get some ice!" There were frantic running sounds. People were yelling, "Oh no!" The emergency truck came up and before they put in I saw the Pepsi executives huddled together in a corner, looking terrified. I remember the medical people putting me on a cot and the guys from Pepsi were so scared they couldn't even bring themselves to check on me.
Meanwhile, I was kind of detached, despite the terrible pain. I was watching all the drama unfold. Later they told me I was in shock, but I remember enjoying the ride to the hospital because I never thought I'd ride in an ambulance with the sirens wailing. It was one of those things I had always wanted to do when I was growing up. When we got there, they told me there were news crews outside, so I asked for my glove. There's a famous shot of me waving from the stretcher with my glove on.
Later one on the doctors told me that it was a miracle I was alive. One of the firemen had mentioned that in most cases your clothes catch on fire, in which case your whole face can be disfigured or you can die. That's it. I had third-degree burns on the back of my head that almost went through to my skull, so I had a lot of problems with it, but I was very lucky.
What we now know is that the incident created a lot of publicity for the commercial. They sold more Pepsi than ever before. And they came back to me later and offered me the biggest commercial endorsement fee in history. It was so unprecedented that it went into The Guinness Book of World Records. Pepsi and I worked together on another commercial, called "The Kid," and I gave them problems by limiting the shots of me because I felt the shots they were asking for didn't work well. Later, when the commercial was a success, they told me I had been right.
I still remember how scared those Pepsi executives looked the night of the fire. They thought that my getting burned would leave a bad taste in the mouth of every kid in America who drank Pepsi. They knew I could have sued them and I could have, but I was real nice about it. Real nice. They gave me $1,500,000 which I immediately donated to the Michael Jackson Burn Center. I wanted to do something because I was so moved by the other burn patients I met while I was in the hospital."