
Sump Pump goes out and makes a mess while VRBO renters are there.
The sump Pump stopped working and made a mess due to something a previous vacation renter flushed down the toilet. How do I handle this Terrible situation with the tenants and any advise in the future?

Is this septic related? In MN a sumo pump collects water that would go in to the basement and mops it away from the house. I was going to suggest setting up dual pumps and probably a battery backed up one, depending why the current one failed.
If you’re talking about a septic pump could you have the cleaning crew clean and flush every toilet a couple times between turn overs? Would the problem have occurred right away? This would prevent it from happening while occupied and make it clear which tenant caused the problem.

Quote from @Andrew Fusco:
The sump Pump stopped working and made a mess due to something a previous vacation renter flushed down the toilet. How do I handle this Terrible situation with the tenants and any advise in the future?
Did it ruin their entire trip, or just a few hours on their last day? Was it an odor issue that was rectified in three hours? I would consider the amount of damage or time their trip was interrupted, see what they are asking for as compensation, and figure out a reasonable solution.
I wouldn't do anything to the previous renter unless you can clearly prove they caused it.
As for the sump pump, consider installing a backup. But if this is the only time it's ever happened in years, I wouldn't spend many brain cells or dollars trying to resolve it. Bill's idea of having cleaners flush the toilets during cleaning should be sufficient to identify any problems between guests.

The renters were there for 5 hours and then this happened around 12 midnight. They opened up all the windows due to the smell and all stayed up stairs to sleep overnight and some of the the people got a Room at the Resort down the street.
Any words of wisdom on how to handle this? Free stay obviously… but what else if anything would you do?