A bulk carrier in the fully laden condition suffered disastrous structural damage in rough seas of significant wave height 8 m, and lost the fore body; she finally sank forty days later. The process of the disaster is analyzed from the viewpoint of hydro-elasticity on the basis of the captain's report. It was concluded that the disaster was cuased by buckling of the upper deck due to whipping after slamming impact in an unhappy superposition of a regular swell and an irregular swell.