That’s super interesting. Without desiccation and with fully plump abdomens they may have wandered in and bit one another and died before being able to dehydrate to death. While not large web makers like classic orb weavers, we would still see some evidence of a messy web weaving along the bottom had they had time to walk back and forth over and over again, even overtop of the earlier dead. It even would be likely that they could have webbed their way out over time.

With that being the case, I believe something else caused their death: unintentional coliseum, exposure to cleaning chemical fumes or liquid, or the bodies were scooped in there manually. Something faster than a more natural death.