I just applied the top border (shell) to a cake that's due tomorrow and it's now sagging/falling off. Some of the BC frosting on the side is also starting to "melt" off. Is there anything I can do to correct this and prevent it from sagging/falling off further?

TIA

Buttercream starts to break down between 80-85 degrees. Do you have your a/c on?

It does sound like it might be melting. That could be due to the temperature its in or even too much liquid in your thin icing can cause it to fall off of the cake. I would take off anything that is already falling so that it doesn't weight down what is still fine and refrigerate it.

Thanks ladies. I did refrigerating it after and it prevented the rest of the borders from completely falling off. However, I haven't completed adding the decorations or the inscription; and I'm worried that during transport, the rest of the borders *will* fall off

I am currently working to fix the fallen borders. Here's hoping it works.

We did have our A/C on, but it probably wasn't cold enough and the frosting covering the cake was pretty thin. I did stiffen the consistency of it for the borders b4 applying it.

Lessons learned for the next cake right? What consistency frosting do you use to ice your cakes...medium or thin or somewhere in between?