  We construct an exact solution describing the collision of two Kaluza-Klein
"bubbles of nothing" in 3+1 dimensions. When the bubbles collide, a curvature
singularity forms which is hidden inside an event horizon. However, unlike the
formation of ordinary black holes, in this case the spacetime resembles the
entire maximally extended Schwarzschild solution. We also point out that there
are inequivalent bubbles that can be constructed from Kerr black holes.
