Wouldn't you be upset if this had happened to your wedding cake five hours before the reception?
I was working with another florist some years ago for a wedding in Morehead City, NC. The reception was taking place in a medium-sized convention center. I was about 80 feet from the cake table when I saw the avalanche. I screamed bloody murder and then began thanking my lucky stars that I had been no where near it when it fell.
We called the home of woman who baked the cake; she was also a caterer and was at that moment delivering food to another wedding about 12 miles away. He husband got in touch with her and she advised him to come and pick up the portion of the cake that was still on the table. She rushed home and supposedly baked another set of layers. This cake was poppy-seed, with a buttery cream-cheese icing. The problem was that she had delivered it to us while it was still warm, and when she put the tiers together, it melted the icing and that's what made it fall.
The cake was supposed to be seven layers, stacked on each other. The bride had requested no supports, such as dowels which are ordinarily used with heavy, dense cakes, especially when they are tall. The reception was supposed to start at 7:00 pm, and the cake fell about 2:45 pm. At 6:45 pm, she walked in with 5 more tiers and also a sheet cake. As she began to assemble the cake again, I was watching - and holding my breath. The first three tiers went together well, but as she laid the fourth tier on top, the sides of the 3rd tier began to buckle. I screamed (once again) and she quickly removed that layer. As before, the cake was still warm.
What we ended up with consisted of one 6" layer atop an 18" layer. It looked more like a sun hat with a wide brim than a cake, especially after I decorated it with flowers around the "crown"! She left the other layers in the kitchen for the staff to cut and serve like the sheet cake.The bride and her mother were remarkably calm about it, and I found out later that the caterer/cake baker was distantly related to them. In my 24 year floral career, this is the only cake with a disaster attached to it!
Be forewarned: if you are ordering a wedding cake, especially one with a dense texture, allow the baker to use the necessary supports or you risk the avalanche above.