Youths smashed an underwater viewing window at a swimming pool, flooding a leisure centre in South Lanarkshire.
Thousand’s of gallons of water poured through the shattered glass before the fire service were able to drain the 50-metre pool.
Police said three people broke into the Dollan Aqua Centre in East Kilbride in the early hours of Saturday morning and caused extensive damage.
The pool, which opened in 1968, was Scotland’s first Olympic-sized swimming pool and contains around 660,000 gallons of water.
It is understood the smashed glass panel – which allows spectators to see swimmers underwater – is five feet below the surface of the pool.
Firefighters used hoses to pump out water from the ground floor of the leisure centre and South Lanarkshire Council supplied sand bags.
Dollan Aqua Centre staff were summoned to the facility in the middle of the night to assist with draining the pool.
A spokesman for South Lanarkshire Council said it is too soon to estimate the cost of the damage but the bill is expected to be in the tens of thousands.
He said: “This was a devastating attack on a much-loved and much-used facility which caused extensive damage. We hope anyone with information about who is responsible contacts the police.”
Police were called to the leisure centre at 12.50am on Saturday morning and they asked the Scottish Fire and Rescue Service for assistance.
Detective Sergeant Martin McKendrick at Cambuslang Police Office said officers were scouring the leisure centre for evidence.
He said: “Our enquiries are still at an early stage and we are gathering CCTV footage from in and around the area at to find out more information on the three men responsible for this incident. The three male youths were wearing dark coloured clothing.
“I would like to appeal to anyone who saw anything suspicious in and around this area, or who has any information on who is responsible to contact Cambuslang Police Office through 101 quoting reference number 0182 of 20th July.
“Or contact Crimestoppers on 0800 555 111, where anonymity can be maintained.”