Why is my Mining Quarry decaying?

Why does it happen?
A Mining Quarry follows the same decay rules as the rest of your base. If it's placed outside a Repairs Cupboard's range - or the Repair Cupboard runs out of upkeep resources - the Quarry gradually loses health and is eventually destroyed.

How to prevent it: place the Mining Quarry on or right next to a building that has a Repair Cupboard, and check the building status indicator on the spot — if building is allowed there, the Quarry is inside the zone. Keep the cupboard stocked with upkeep resources.

Common mistakes:
Placing the Quarry far from base, outside any Repair Cupboard range - it decays. Letting the Tool Cupboard run empty. Forgetting to top up the Repair Cupboard after a long offline session.