Thanet District Council could be facing a big fine, after admitting some if its maintenance staff were injured at work.
They developed "vibration whitefinger", which used to be a common condition among miners in Kent who used pneumatic diggers and drills.
The Health and Safety Executive has prosecuted Thanet for failing to protect its staff properly.
It is a scar on the Kent landscape - 27 years after it closed the ghost-like shell of Snowdown colliery still serves as a reminder of a once great industry that employed more than 3,000 across East Kent. Many ex-miners blame Mrs Thatcher for the closure of Kent pits.