The Omagh Bombing Inquiry is examining whether the single worst atrocity of the Troubles could have been prevented
Twenty-nine people, including a woman expecting twins, were murdered in the Real IRA attack on 15 August 1998
This is the fourth week of hearings
Edited by Conor Neeson. Warning: This page contains distressing details
Simon says a neighbour invited them in and offered them a hot chocolate which "I thought was a bit of a strange thing to do".
"I suppose when you're in shock you don't do what you're supposed to do."
Simon says he had a lot of blood on his t-shirt.
He says his girlfriend tried to phone her mum and dad to let them they she was okay.
He says the phone lines weren't working.
Simon's neighbour was talking about destroying his footage but Simon and his girlfriend told him it could be important "to show people what happened" and also for evidence for the police.
"That's the footage you see now of the Omagh atrocity."
Simon says he then met up with his neighbour, who also had a camera.
He says his neighbour followed him about with the camera as he made his way between casualties.
There was another man with a camcorder and Simon says he told him to go down the street and record what had happened so "the world could see what these people had done to us".
Simon says he walked past where the bomb went off and saw most of those who were killed.
Simon says he came upon a number of bodies who he then realised were dead.
Those images "will remain with him for the rest of his life", he says.
A fire engine arrived and a fire officer got out. Simon told him it was serious and that there were at least nine fatalities and more injured and trapped in businesses.
"He was completely silent. I don't know if I wasn't making a lot of sense or he was taking in what had happened."
He was probably assessing the situation, Simon says.
Simon says he came across a young boy and went to check his pulse "and realised there was nothing there".
He says this was the first time he had done this.
"That was hard to deal with."
He says the look on the boy's face "haunts" him to this day.
The smoke started to clear, Simon says, and the scene was "a lot worse than I thought it was to begin with".
He moved up the street to help other victims.
Mr McLarnon says he had "no idea" what to do with the young woman.
He said he was "amazed" that she was awake and asking for help.
He says he told her the ambulances would be there soon and moved on which he regrets.
Simon saw a lady crying "my leg, my leg".
Her leg was held on "by skin only".
Another girl beside her had "two limbs virtually amputated and very serious injuries".
"I didn't know what to do with her. I had limited first aid experience.
"I had been shown how to deal with an amputated limb but not two."
She also had a deep wound to the neck and had possibly lost an eye.
Simon says he came across Philip Marshall, the police officer.
He says he recognised Mr Marshall from a news report about the inquiry's proceedings yesterday at which Mr Marshall gave evidence.
"He was very visible at the scene."
"I noticed he had a large blood stain on his shirt."
He saw a traffic warden with his clothes partly blown off, trousers split at the back, who was helping move damaged vehicles.
"There was an Ulsterbus trying to get through and he was trying to clear the way to get emergency services through."
He was "taking control and doing his best".
Simon says the staff of a chemist were tending to people on the ground.
He says he moved past these people.
Simon says he should have stayed with the man to make sure he was okay but he left to see if he could help other casualties.
"In retrospect it would have been better to stay with that man to make sure he got to hospital."
Simon says as he approached the site of the bomb there were people running past him away from the explosion and others - like him- running towards the site to try to help.
He says the second casualty he came across was a man lying on his back with a teenager holding his head.
He said the man had a large injury on his arm.
Simon says he showed the teenager how to try to stop the bleeding.
Simon says he and his neighbour went to see if they could help and were "met with a sea of glass".
It looked like glass had been "sucked out" of businesses' windows.
This was from the blast zig-zagging up the street, he says.
He says there were people everywhere but there was a lot of smoke so it was "hard to make people out".
The first casualty he saw was a man who ran past them with a small child in his arms.
There were people running towards the bomb "to try to help" and a lot of people injured.
He says that after a brief period of silence they were aware of people screaming.
He also described seeing "very dark smoke" from the area of the explosion.
He says it was almost as if the sun had been blocked out and there was a strong smell that was "acrid" and made you cough.
The adrenaline kicked in, Simon says, and he ran downstairs.
Everywhere was "engulfed in black smoke".
He laced up his boots, and went into town with a neighbour who had a camcorder.
He had been planning to video his daughters in a summer fete.
Simon says he had experienced one bomb before.
"I remember the feeling you get from the shockwave but this way in excess of what I had experienced in the past."