My son flushed toilet after # 2. We both were outside working for about an hour. We came in and were horrified to find that toilet had been overflowing the entire time. We cut off water, plunged toilet.
So much water had been dumped that it had ruined laminate floors. My landlord is holding us responsible for damage.
My question is, shouldn't toilet have stopped overflowing long before? The next day we discovered that water kept running in bowl. When landlord came she discovered chain somehow had stopped flapper from sealing. She still says we are responsible because son stopped up toilet. I used to keep plunger in that bathroom because if easily stopping up. It had seemed to stop. Is this a toilet malfunction or somehow my fault as renter. I want to do right thing.

You are responsible for it because it was something your son did... even if it was accidental. Because if he had not walked off it would have been able to have been stopped before damage happened.

Do you have renters insurance? Was any other units damaged... such as an apartment downstairs.

Insidently... yes normally a plugged up toilet doesn't always equal a flood.. unless someone double flushes. Unless you have the older toilets with the big tanks. The low flush units don't do it anyway.

The ones in my house (low flush) hold enough water in the tank to fill the bowl... quite high in fact... but not enough to overflow.

If the toilet was not stopped up, even if water had keep running, it would have sent down the sewer, so two issues, one, what stopped up toilet, that was the first and main cause of the over flow.

Next the chain getting caught was the other, but again, this is common and the user needs to be aware of it.

Sorry, sounds like you may be held responsible

Renters insurance will pay for it. If you knew there was a problem with this toilet your son probably should have waited until it stopped flushing before walking out.

I'm a landlord. If you had reported "stop up" problems to me I would take some responsibiity. If you did not I would say it's all on you.

If your renters doesn't cover it, ask the landlord if his insurance does.