Failed when one found the floor wouldn't support one? (4,7)

'failed' is the definition.
The definition and answer can be both to do with social activities as well as being past participle verbs.
Perhaps they are linked in a way I don't understand?

'one found the floor wouldn't support one?' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'floor' could be 'fell' and 'fell' is present in the answer.
This explanation may well be incorrect...

'when' is the link.

Can you help me to learn more?