A coroner hearing the case of a Royal Marine killed by "friendly fire" in Iraq has ruled his death was caused by serious failings by the military.
Marine Maddison's river patrol boat was hit by British missiles
Christopher Maddison, 24, from Scarborough, was killed by his own side during a river patrol in 2003.
Coroner Andrew Walker said the marine, based in Plymouth, had been let down by those in command.
Mr Maddison's mother said the Ministry of Defence had failed in its duty of care to her son.
An initial investigation carried out into Mr Maddison's death found that the marine had been killed in an enemy ambush.
That finding was called into question by a BBC documentary and the case was reopened.
An internal inquiry later concluded Mr Maddison had been killed by his own side after a series of operational errors.
Oxford Coroner's Court heard missiles were fired at the marine's boat after Royal Engineers soldiers manning a crossing point upriver were told they were being approached by two enemy craft.
Mr Maddison died from shrapnel wounds inflicted by a missile fired from the crossing point on the Khawr Az Zubayr river in southern Iraq.
Recording a narrative verdict, Mr Walker said there were serious failures in the chain of command at the crossing point.
He also said there had been a failure to provide a liaison officer to keep soldiers at the crossing updated of the patrol's whereabouts, and a failure to provide adequate communication between the crossing point and the two patrolling craft.
He said Mr Maddison was "let down by those who were in command and by the communication system in operation at that time".
In a statement read during the hearing, the marine's mother, Julie Maddison, said leadership had fallen "far below" what could reasonably have been expected.
She said: "The lack of duty of care to possible risks and consequences even I, as a lay person, could have foreseen, effectively created an obvious chain of events which could have led to further loss of life."
Speaking after the coroner's ruling, Mr Maddison's father Les Towell described the initial investigation into his son's death as "a farce".
He said: "We have been told that steps have been taken to minimise the risk of this type of tragedy reoccurring.
"We have our doubts about this, but, if one small change results in one life being saved, then Chris' life will not have been in vain.
"Royal Marine Maddison can now stand easy. Chris, goodnight son, sleep well."