The man who played a heroic role during the Oct. 1 rampage at an Oregon community college that left 10 people dead has come out with his own narrative of what happened that fateful day.

In a Facebook post he wrote on Thursday, Army veteran Chris Mintz said he still wondered how he made it out alive despite getting shot five times by the gunman, Chris Harper Mercer. He said the bullets struck both of his legs, his abdomen, shoulder blade and left finger.

He said he also could not explain why Mercer, seeing him still alive despite the five bullets he pumped into his body, did not finish him off.

"I'm still confused why he didn't shoot me again," Mintz said.

Mintz began his Facebook post by thanking everyone who extended help to the families of the victims of the Umpqua Community College massacre in Roseburg, Oregon.

Ever unassuming, Mintz said he is releasing his account of the incident on Facebook and not to any media outlet because he is not after publicity. "This isn't about politics, this isn't about me, this is about a community healing. I am so happy with how the community has bonded and supported everyone during this healing," he said.

Mintz then began recalling the events that day. "It started so normal, the day that is."

He said he was in his writing class, laughing with his teacher and other students, when they heard yelling in another room.

"My teacher walked up to the door that connected our classroom and asked if everyone was OK," he said. "No one could tell what the yelling was."

When his teacher knocked on the door, gunshots suddenly erupted. His classmates hurriedly left the room in fear.

Amid the ensuing chaos, Mintz said he tried to help the panicking students, opening the door of their class and waiting for everyone to leave before joining his classmates.

Upon reaching the library, a school counsellor warned them it might not be safe there and advised them to go to the other side of the campus instead where it was safer. Mintz volunteered to warn the students not to proceed to the library.

"I ran in and told everyone they needed to leave and go to the other side of the campus," he wrote. "I ran through the book aisles while yelling and pushed the emergency exits ... open and ran through them and back down towards Snyder Hall."

Despite knowing that the gunfire was coming from Snyder Hall, Mintz ran towards the scene of the shooting to warn fellow students.

"... People across campus were walking around like nothing was going on, so I continued yelling at them to get out of there to leave," he said.

Upon reaching Snyder Hall, he said he still didn't know where the gunman was.

"I got to a classroom and looked into the door because it had a glass slate," he said. "A guy that was farther away and hiding behind cars startled me and yelled, 'Don't man, he's going to shoot you, man.' "

Mintz peeked inside and saw a student covered in blood, screaming.

"I motioned my finger over my mouth, communicating to be quiet and motioned both my hands down for them to stay down," he wrote.

As the police sirens began wailing in the distance, he saw a man in a parking lot. "You need to go get the cops, tell them where we're at," Mintz shouted at the man.

Then suddenly, the shooter showed up. He instinctively ran towards the direction of the gunman who was wearing a black shirt and glasses and had a shaved head.

"He leaned half of his torso out and started shooting as I turned toward him," he said. "He was so nonchalant through it all, like he was playing a video game and showed no emotion."

The shooter aimed his gun at Mintz as he was moving towards him and began shooting him.

"The shots knocked me to the ground and felt like a truck hit me. He shot me again while I was on the ground and hit my finger, and said 'that's what you get for calling the cops,'" Mintz wrote.

Lying on a foetal position and unable to move, Mintz told the gunman, "I didn't call the cops man, they were already on the way."

The gunman leaned further out of the classroom door and tried to shoot his cell phone which he had dropped. He yelled at the gunman, "It's my kid's birthday man!"

Mintz saw the shooter point the gun right at his face, but he didn't pull the trigger as he suddenly retreated back into the room.

"I tried to push myself back against the classroom door but I couldn't move at all. My legs felt like ice, like they didn't exist, until I tried to move. When I moved pain shot through me like a bomb going off," he said.

Finally the gunfire stopped as police officers in tactical gear stormed in. Students scampered out of their classroom where the shooting took place, some covered in blood. A friend saw him and broke down into tears.

" I think she tried to pray with me, the only thing I could say was 'it's my son's birthday. Please call my son's mom and tell her I can't pick him up from school today,' " he said.

He later found out that the gunman, Mercer, killed himself when police closed in.

Mintz said he is now recovering from his wounds. Before finishing his post he thanked the police, hospital workers and other first responders. "They are the real heroes, they saved us," he wrote.