Adams was riding his bicycle out of the parking lot Monday night when he turned to wave at a student. While looking back, he biked into the end of the yellow bar that drops down to allow cars access to the parking lot. The bar impaled him in the stomach.
Students rushed to his aid and called 911, but he died of his injuries a few hours later at a hospital.
"It’s like a nightmare," Adams' son, Joe, told CBS News. "I keep waiting to wake up, just hasn’t hit me all the way."
Rio Linda athletic director Mike Morris told the Sacramento Bee: "Marion was the most popular and nicest man on campus. Just a great guy. It's a huge loss, devastating to our community. He's an example of how great Rio Linda is as a school and community. He couldn't wait to come back here. This place meant everything to him."
Adams is survived by his wife Kathy, son Joe and daughter Sarah, two grandchildren, his mother, Edith, and seven siblings: David, Steve, Janice, Caroline, Betty, Lorraine and Mark. Memorial services are pending.