What workplace accident made society aware of danger in the workplace?

Theres more than one so do you want a few or just one

Greece lies partially on islands, which are hard to travel to but easy to defend, and in valleys, which also are hard to travel to but easy to defend. This lead to a more partitioned civilization, i.e. rather a big number of city-states and not to one big empire as in the case of the Romans and the Greeks.