A community centre in Skewen has been left completely flooded after vandals put a hose pipe through an air vent.
All seven rooms, including the kitchen, in Coedffranc Community Centre was left under an inch of water. Vandals had also put plugs in the sinks of the outdoor toilets and turned the taps on.
People responsible for the bowls pavilion discovered the damage on Monday morning, January 27.
The centre is used by a number of groups including a bowls team, old age groups and disability groups.
Del Hastings, a health and safety officer at Coedffranc Town Council, said it was the vulnerable people who used the centre as a lifeline who were being punished.
"We had to cancel sessions with the old age group, special needs group and bowls club. And for some of these people it's the only time they get out of the house and socialise with others. It's just mindless vandalism that is only spiting people who enjoy these groups and depend on them,"
"I couldn't believe it when we found it, I was gobsmacked and couldn't believe people had gone to so much trouble to do this. They've climbed over the gates and then over another fence, got the hose from the greenhouse and dragged it another thirty yards to do this, and for what?" added Mr Hastings.
The full extent of the damage is not yet known, but children's toys and some of the kitchen's electrical goods will now need to be replaced.
The health and safety officer said: "Luckily the electrics were all off or it could have been a lot worse but because it's a sort of portable building then we may not know the damage for months. The flooring is all soaked through and we could see in a few months that it has all rotted. There was around an inch of water in seven rooms, it's a lot of water that's difficult to dry out."
"'Why?', is what we keep asking, why would someone go to so much trouble? These actions took a lot of time and effort, I hope they are proud of themselves," added Mr Hastings.
The incident has shocked the local community with some saying it's caused "havoc" in the area.
One resident, Helen Jones, said: "This is absolutely terrible, I hope you find those responsible and make them, or if it's children, their parents, pay for the damage. It's such a lovely park and so well used. It's a shame the minority are spoiling it and causing costly havoc."
Another resident, Alyson Thomas, added: "These people take a perverse pleasure in ruining things for residents. With the Carnegie Hall out of action community groups have no choice but to use the pavilion and now that is threatened."
South Wales Police said they were aware of the incident and were investigating the matter.