Severin Sampson was injured when huge amounts of snow and ice fell down on him on the Friday before Super Bowl XLV at what was then called Cowboys Stadium in Arlington.
Sampson -- who is suing the Dallas Cowboys, the stadium architects, the NFL, and others for millions of dollars in damages -- took the witness stand on Tuesday.
He told the jury he was outside the stadium to deliver equipment on February 4, 2011.
"I heard a loud rumble. I thought it was thunder. Then — all of a sudden — I heard a crash. Boom! Boom! Boom! It sounded like a Howitzer," he recalled. "I saw a big flash of white. I couldn't see anything but a plume of white."
After that, Sampson said he continued with his work, assuming everything was safe.
"Nobody told me there was still ice falling from the roof," Sampson said.
He said as he was leaving the stadium following his delivery, two men in red jackets started motioning, encouraging him to move more quickly. But then he said one man told him to hold up and wait.
"That's when I saw a boulder, and no time to do anything," Sampson said. "I looked up and I saw something the size of a Volkswagen and a sheet of ice behind it. It was the size of a baseball infield. It was huge."
Sampson testified he couldn’t outrun it, so he ducked and covered.
The next thing he said he remembers was being in an ambulance.
"The medic pulled a towel away from my head and I could see it covered in blood," Sampson said. "Scared the crap out of me."
He said after arriving at the hospital, he kept setting sick and his head was spinning. He said the doctor in the emergency room told his skull had been fractured.
"He said, 'This injury, we only see in the morgue,' and that scared me," Sampson said.
Defense attorneys say Sampson signed waivers, went to safety meetings, and should have taken more precautions -- including wearing a hard hat.
The defense maintains Sampson was simply in the wrong place at the wrong time, and what happened is nobody's fault but his own.
This case is expected to go to the jury in the next couple of weeks.