Southampton City Council's leader has described how he overpowered a sailor who shot dead one crewman and injured another on board a nuclear submarine.
Royston Smith was on a guided tour of HMS Astute in Southampton docks when the shooting began on Friday afternoon.
Councillor Smith said the gunman had already fired his gun several times when he wrestled him to the ground.
A Royal Navy serviceman has been arrested. The injured crewman is said to be in a life-threatening condition.
Eleven children were on the quayside at the time of the shooting, at about 1210 BST on Friday, and were due to board the submarine.
'Line of fire'
Mr Smith told the BBC how the man's gun went off during the struggle and said he was lucky not to have been wounded.
The council leader, who once served in the RAF, was aboard the submarine as part of a civic party, which also included the city council's mayor Carol Cunio and chief executive Alistair Neill.
Describing what happened, Mr Smith said: "We were in the control room when someone entered and there was an exchange of words.
"He [the gunman] stepped out with another man and two shots were fired and then he entered the control room again and began shooting again.
"It was a very small, confined space - we would struggle not to be in the line of fire.
"He had a magazine with 30 rounds in it so I took the view that someone had to stop him.
"At some point I decided that the best form of defence was to try to disarm him. I guess I'm lucky he did not hit me.
"He fired again while I had hold of the weapon. I had a strange feeling. I was not sure if I'd been hit - it didn't hurt - but I wasn't thankfully.
"I pushed him against the wall and we wrestled, then I pushed him into another wall which resulted in him going to the ground and I managed to get the weapon from him and threw it aside under a table.
"I shouted for someone to help as I held him down and my chief executive was the first to come, and he did a remarkable job of restraining him.
"After a minute or two he became compliant. He was thrashing around and was not going to give up easily."
Mr Smith said he was not aware that anyone had been shot at the time.
"It was supposed to be a good day - welcoming a ship to Southampton - but it turned into a tragic day. I don't know how it could happen.
"I think about the families as they have had the worst news possible", he added.
Hampshire Police are interviewing about 30 potential witnesses to what happened on the submarine.
A force spokeswoman said the shootings were not linked to terrorism.
The 97m (318ft) HMS Astute, the UK's newest nuclear submarine, is based at the Faslane Naval Base on the Clyde.
Astute was named and launched by the Duchess of Cornwall in June 2007 before being welcomed into the Royal Navy in August last year at a commissioning ceremony at Faslane Naval Base on the Clyde.
The vessel has been berthed in Southampton since Wednesday for a five-day official visit.