According to official sources, the total stolen had an estimated value of up to £14 million, of which only £4.3 million has been recovered. The heist was planned and carried out by six elderly men who were experienced thieves, all of whom were arrested, pleaded guilty and received prison sentences in March 2016. Four other men were also tried on suspicion of involvement; three were found guilty and sent to prison, while the fourth was cleared.The burglars worked through the four-day weekend of the Easter Bank Holiday, when many of the nearby businesses (many of them also connected with Hatton Garden's jewellery trade) were closed. There was no externally visible sign of a forced entry to the premises. It was reported that the burglars had entered the premises through a lift shaft, then drilled through the 50 cm thick vault walls with a Hilti DD350 industrial power drill. The police first announced that the facility had been burgled on 7 April, and reports based on CCTV footage (released by the Daily Mirror before the police released it) state that the attack on the facility commenced on Thursday 2 April. The video showed people nicknamed by the newspaper as 'Mr Ginger, Mr Strong, Mr Montana, The Gent, The Tall Man and The Old Man'. On 22 April, the police released pictures of the inside of the vault showing damage caused by the burglary, and how the burglars had used holes drilled through the vault's wall to bypass the main vault door.