A coroner has recorded narrative verdicts on five men killed in a crash on the M1 when three armoured vehicles fell off their transporter.
The transporter crashed after being hit by a car
A Honda Civic hit the back of the transporter on the M1 in Leicestershire causing the tanks to fall off.
The inquest highlighted inadequate training given to transporter drivers who carried three instead of two tanks.
But families of those who died in June 2003 said the verdict should have been unlawful killing.
Assistant deputy coroner Martin Gothridge said it would have been inadequate for a verdict of accidental death for a "truly horrific and horrendous" incident.
A narrative verdict allowed the coroner to set out factually what might have caused the deaths as well as defects which might have been contributory factors.
'Unsafe and dangerous'
He reminded the court that drivers employed by the civilian transport contractors Elliot Sargeant received no formal training on how to secure the armoured vehicles to the trailers.
The company had not followed best practice by carrying three rather than two mini-tanks on the trailers and doubts had been raised about the way the vehicles had been secured, Mr Gothridge added.
After the inquest, Karen Starkey, a spokeswoman for the families who died in the crash, said they were disappointed that Elliot Sargeant had put lives at risk "by routinely carrying three tanks on transporters across the country knowing full well it was unsafe and dangerous".
The five men killed were Paul Evans, 37 and Craig Mears, 33, from Great Wyrley, Staffordshire; Daniel Bradley, 21, from Melton Mowbray, Leicestershire; Wayne Buckley, 44, from Ossett, West Yorkshire; and Christopher Green, 29, from Sutton-in-Ashfield, Nottinghamshire.
Alec Bradley, whose son was one of the victims, said he would be asking the Crown Prosecution Service to review the file on the incident in the hope that it would lead to a prosecution.