Well today it happened. I always hoped I would never witness a MC accident, but today I did, and it was bad. I seen it first hand and it was like slow motion. I was heading south and came to a red light. There was east and west traffic going at 45 MPH as they had the green light. On my left, there was a MC facing west in the center lane waiting to turn left. (South) He appeared to be waiting for the eastbound traffic to pass so he could turn south. His motorcycle died, I do not know if it was a result of himself or other reasons, but he started it and apparently thinking he was holding traffic, he turned left directly in front of a car heading east. No way did he see him as the car was entering the intersection when he took off. The driver of the cage had no chance to react or avoid hitting him. I seen the entire thing happen right in front of me. He and the bike went up onto the windshield, smashing it, and then I swear 15 feet in the air and then slammed down on the concrete. I immediately called 911 and to my disbelief, someone had already called. I parked my truck in front of him and the MC to avoid oncoming traffic from coming through. He had a full face helmet, gloves and a long sleeve jacket on, but I am afraid it was not enough. He was alive when the paramedics showed up. They must have been there in less than 90 seconds, and that is no exageration. I only can think their station was around the corner.There was another man there who was holding his head still as he was trying to move. I could physically his chest cavity expanding from internal injuries as he lied there. I do not know yet, but I think his chance of survival is very low. I then seen the driver of the car a few hundred yards down the road sitting on the curb holding his head and shaking. Nobody near him. I went there and sat next to him on the curb and for the first minute said nothing, just sat there with him. He looked at me and said I am so sorry. I told him I ride and that I can honestly say he had no chance to avoid this. I felt terrible for him, but I think the fact I was sitting with him helped a bit. A young man in his late twenty's maybe. Guys, All I can think of is the MC rider stalled his engine, after starting it probably thinking he is holding traffic at a green light tried to hurry into the turn. He no way seen the oncoming car as there was no chance to make it. This is a horrible day as I will never forget it. I wish I had not seen this, but I can promise you, after you do, things are not the same for me. I hope and pray the rider is alive. I also seen something that I never thought of, and that is the distress of the other driver, even when not at fault. My message to all of you is please ride safe.