Place it at the collapse itself, after the build-up and before the reaction shot, then follow it with Oh No TikTok Song for the failed attempt and Coffin Dance Meme Sound to close out the defeat with a joke.
About this sound
This is a short voice clip of about six seconds in which a playful, exaggerated voice calls out kaboom, there goes your tower as a structure falls apart. It feels silly and lighthearted, turning a sudden loss into a laugh instead of a frustration. The line comes from Roblox tower gameplay, where it is used to mark a build collapsing in short-form edits.