Found some open door at the birthday party in the vault and went through it and i fell through the floor and it placed me at the end area of the vault. it also went full savagery on my frames. Can anyone tell me what happened?

The whole vault section is connected in a single coc so if you fall out of bound anywhere from inside the vault (baby,kid,teen,19 yo), you actually always respawn at the exact same location (next to the bucket). This is how any% is done.