The shell, fired from a 155mm gun in a close fire demonstration at Suffield, Canada, in June 1994, killed Corporals Robert Hawksley and Martin Bailey, of the Queen's Royal Lancers.
Facing a court martial at Bulford, in Wiltshire, accused of their manslaughter is Major Jonathan Ginder, 36, from Newmarket, Suffolk. The gunnery instructor of 29 Commando Regiment, Royal Artillery, denies both charges.
Captain Francis Morelli, the forward observation officer for the shoot, who was in another trench, told the hearing how he heard a number of rounds explode which seemed to be landing where they should have done.
"Almost immediately after, another round exploded very much closer to where I was and I got showered with a lot of mud and rock," said the captain, who has since left the Army and is living in Germany.
"I did not know exactly how close but I knew it was close. It was quite unexpected."
He told the court that heshouted to ask if everybody was all right and was told a trench had been hit. He added: "A round had landed so close to a trench, the trench had completely collapsed."
The captain also described how someone had managed to get his hand down inside the collapsed trench and said he could feel a pulse, but when the two soldiers were taken out they were dead.
Lieutenant-Colonel Richard Austin, for the prosecution, told the hearing that Major Ginder had a duty to care for the two soldiers and anyone else in the area and the court had to decide if he had carried out his duties properly.
The hearing was adjourned until today.Reuse content