Hammer-wielding vandals managed to get into a tower block and smashed 33 windows on six floors.
The vandals got into Chaucer House in Sutton town centre on Sunday and went from the eighth floor to the second floor smashing windows in communal areas with a hammer.
It is not clear exactly how the three youths got into the block but it is believed they could have taken advantage of a problem with the entry system on the doors.
It is not the first time the block, off Chaucer Gardens, has fallen victim to vandals. In October last year a 13-year-old arsonist started a fire on the ninth floor.
Damage from last year's fire
The resulting blaze was so hot it shattered windows and caused £5,000 of damage. The boy was given a referral order.
The most recent vandalism happened between 3pm and 4pm on Sunday. A neighbour living in the block, who asked not to be named for fear of reprisals, said: "We're supposed to have key fobs for the security doors but those don't work.
"Sutton Housing Partnership repairs them but then they just break again.
"I thought it was just the windows on my floor but then I went outside and saw it was all the windows from the second to the eighth floor. They all had hammer holes in them.
One of the broken windows
"It's not nice, I don't feel safe. I wonder what's coming next."
Sutton Housing Partnership (SHP) said it plans to replace the front doors and install extra security measures at part of a £2million refurbishment of the tower.
A spokesman added: "Following the incident of vandalism at Chaucer House on Sunday we have been working with the police to identify the perpetrators.
"CCTV footage of the incident has been reviewed and we have clear images which we hope will support the police to catch and prosecute the vandals.
"Windows in the communal areas at Chaucer House have been made safe and works to repair the broken glass to 33 windows will be carried out as soon as possible."