We present SMM coronograph/polarimeter observations of the coronal transient of March 15-16, 1980, which show a bright front convex toward the sun propagating out through the corona at 175 km s-1. A fan-shaped bright region connecting this front to the inner corona collapses into a narrow bright ray over the next few hours. We interrupt these observations as resulting from the disconnection of magnetic loops from the underlying prominencelike loop structures seen rising earlier in the event. Other similar ''inverted arches'' exist in the C/P data but are usually seen with poorer temporal resolution.