A judge has sentenced four men for a foiled Christmas time armed robbery at a PC World store.
All four were caught in the act when police, who knew about the robbery, let off a flash grenade, startling the robbers.
Delivering a jail term for three of the defendants, judge Ann Mulligan, called the situation "tragic".
Former Fulham branch PC World employee Hamza Dahir, 25, and Ricco Powell-Allen, 21, had previously admitted to conspiracy to rob and possession of a firearm during the 7am raid on December 27 in New Malden last year.
Co-defendants David Tesfaalem, 22, of Stannard House, Plough Lane, Wimbledon, admitted conspiracy to rob and Liban Ali, 25, of Pennethorne House, Wye Street, Battersea, admitted conspiracy to burgle.
They were all sentenced on Friday in front of a packed public gallery full of friends and family at Kingston Crown Court.
Judge Ann Mulligan said: "It seems to me in this case that it is really rather tragic. You Mr Dahir, a man of good character and 25 years of age, and you Mr Ali, 25 years of age, also of good character.
"Mr Powell-Allen and Mr Tesfaalem 21 years of age - previous convictions but none like these. My view relating to the four of you is that this is indeed a tragedy.
"All four of you have considerable family support and all four of you have let your families down enormously."
The court had previously heard there had been £70,000 in a safe at the Burlington Road shop, money in the tills and thousands of pounds worth of electrical goods at the store.
The defendants, however, would not have known the safe had been set to a timer and would not have opened before 10am even if they had got as far as into the building before police stormed the area.
Dahir, Tesfaalem and Powell-Allen - who was also found with a hammer, were caught by police, who fired a flash grenade which nearby residents mistook as gunshot sounds.
Nobody was hurt in the attempted robbery.
In mitigation for Powell-Allen, of Summerley Street, Earlsfield, defence counsel Paul Crampin said: "He had been recruited the evening before. Pardon my expression - to make up the numbers."
Speaking on behalf of Somalian-born Dahir, of no fixed address, Ian Henderson said: "He wants to do his time and then see the light at the end of the tunnel."
Ali, a father-of-three, who had been the would-be getaway driver, was arrested three miles away by police.
He had carried out early morning surveillance of the electrical retailer shop on three occasions in December, the court had previously heard.
In fact, he had even received a message from an unknown person the night before saying: "Yo what’s happening bro or is it off so I can call it a night – getting late out here."
Judge Mulligan received letters from the defendants and their families ahead of the sentencing.
Of the themes in the letters, she said: "One is remorse and regret and the other from families is 'please be lenient, please be lenient.'
"But I must make clear I have a public duty."
Having been told the gun used for the attack had not been in good working condition and may not have been useable, judge Mulligan said: "Those members of staff that were there were simply terrified - a serious serious offence."
Powell-Allen was sentenced to six years in jail, Dahir was given five years and Tesfaalem, who had breached an earlier suspended sentence after being found with 11g of cannabis in his underwear last year, was handed four years for his involvement.
Ali was allowed to walk free and given a two year suspended sentence, suspended for two years based on his lesser involvement.
Two of the defendants shook hands with him before they were led to the cells.