[Flick Lives]

From the video, it looks like the deck was just above the shoreline. I wouldn’t be surprised if salt spray dissolved the joist hangers. Unless the used stainless steel hangers and nails, the salt air will corrode them.

[Bell Bouy II]

Does the rust on the visible bolts and other hardware give you a clue ?

[colorado tanker]

From the video the metal in the balcony showed some serious rust.

Also, the partiers were young people - I didn't see anyone obese.