Things to be expecting in old buildings:
5) ”Mantraps” or “Legbreakers”
In this particular case, otherwise known as “grease traps”. We’ve also seen this hazard at industrial sites in the form of water-filled basements left behind where buildings were torn down and the rubble removed. Especially insidious were those where the cement ceiling over the basement was left intact except for places where holes already existed or were knocked through it during the process of demolition. If you’re not careful, one moment you’re fine and the next you’re falling into a ten foot deep water-filled pit.
Being aware of your death traps if VERY important