DEARBORN (WWJ) – A Secret Service agent who was on duty when President John F. Kennedy was assassinated shared his version of that fateful day as the nation prepares to mark the 50th anniversary of the tragedy.

Former Secret Service Agent Clint Hill was the man seen in the Zapruder film frantically climbing onto the back of President Kennedy’s limousine as shots rang out on the streets of Dallas Nov. 22, 1963.

Hill gave a first-hand account of the turning point in American History during a lecture Tuesday at the Henry Ford Museum in Dearborn.

“I was on the left-hand front position and about that time, I heard an explosive noise over my right shoulder from the rear. I realized something was wrong,” Hill told the captivated crowd. “The president grabbed at his throat, so I jumped from my position and ran toward the presidential car in an effort to get up on top of the back of the car to form a shield or barrier to prevent anything further from happening to either the president or Mrs. Kennedy.”

Hill said he was approaching the presidential vehicle when a third gunshot was fired.

“I heard it and I felt it because it hit the president in the head. It was so explosive in nature that blood and brain matter and bone fragments all erupted right out of the wound. It came over the back of the car, onto Mrs. Kennedy and onto myself,” he said.

That’s when Jackie Kennedy famously crawled onto the back of the limousine.

“Why did Mrs. Kennedy come up in the back of the car? Because she was trying to gather some of the material that came off the president’s head and was on the back of the car,” Hill said.

At that point, Hill said he realized just how grave the situation had become.

“I could see the president’s eyes were fixed and there was a hole in his skull. I could see through that hole and there was no brain matter left in that whole area of the brain, so I assumed it was a fatal wound. And I turned and I gave a thumbs-down to the follow car crew to let them know just how serious the situation was,” he said.

They rushed President Kennedy to the hospital.

“Mrs. Kennedy had ahold of the president and wouldn’t let go. I pleaded with her to please let us help the president, but she wouldn’t let go. She didn’t want anybody to see the condition he was in because it was horrible. So, I took off my suit coat and I covered his head and as soon as I did that, she let go. We rushed him into trauma room one, doctors came running from all over the hospital, trying to do everything they could to revive him,” he said.

While doctors were battling the odds, Hill placed a phone call to then-Attorney General Robert Kennedy, the president’s brother.

“I said ‘Mr. Attorney General, there’s been a shooting. The president’s been shot, the governor’s been shot, we’re in the emergency room at Parkland Hospital.’ He said ‘Well, how bad is it?’ I did not want to tell him that his brother was dead, so I simply said it’s as bad as it can get and when I did that he just hung up the phone. And that’s how he found out about his brother,” he said.

While many Americans still believe there was a conspiracy to kill the president, Hill said all of the evidence points to one man alone.

“There were only three shots fired that day in Dealey Plaza. All three shots came from the same location, the sixth floor of the Texas School Book Depository, they were all fired using the same rifle and they were all fired by the same individual, Lee Harvey Oswald, and no one else,” he said.

In remembrance of President Kennedy and to mark the anniversary of his death, the Henry Ford Museum — home of the presidential limousine from that fateful day — will waive admission fees for everyone on Friday, Nov. 22. For more information, visit www.thehenryford.org.