The fastest projected rates of sea level rise appear in models which include “the marine ice cliff instability (MICI),” a hypothesized but mostly unobserved process defined by rapid, brittle failure of terminal ice cliffs that outpaces viscous relaxation and ice-shelf formation. Crane Glacier’s response to the Larsen B Ice Shelf collapse has been invoked as evidence of MICI, but sparse data coverage of that event in space and time has hindered interpretation of the processes controlling terminus retreat. Using available remote sensing data, we deconstruct Crane’s retreat, arrest, and regrowth over the last two decades. Much of Crane’s terminus retreat occurred in floating, not grounded ice, but calving accelerated by at least 55% during the 2 years following ice shelf collapse, consistent with a positive geometric feedback. If calving occurred by cliff failure, maximum cliff heights would have been 111 m, only consistent with process models that incorporate damaged ice.