The mechanism by which bubble domains collapse and stripe domains chop has been observed in magnetic bubble garnet materials. Single 10‐nsec‐exposure transient pictures taken during the collapse process show that the mechanism of stripe chop and bubble collapse is dominated by the formation of a head‐on wall structure which is nucleated, presumably at one surface, and propagates through the film. In collapsing bubbles, the structure can form before the unstable equilibrium radius is reached. For long stripes in both implanted and as‐grown films, it does not form uniformly along the stripe; thus, sections of stripe will chop to form bubbles. The head‐on wall structure is statically unstable and can only persist for tenths of microseconds.