A steam-tube of the main boiler exploded on a ship lying in the harbour of Hamburg. The steam temperature was 283 degrees C. Cutaneous and severe inhalational scalding occured in the 27 fatalities, the men dying after different intervals. This paper deals with the pathological findings in the respiratory passages and the lung, describing the topographical extent of direct thermal injury and the temporal course of tissue reactions. In cases of instantaneous death coagulation necrosis of the tracheal and bronchial wall was found to extend to alveolar ducts in central parts of the lung. The lung parenchyma showed marked congestion, alveolar edema and desquamation of alveolar epithelial cells. Death occured due to acute pulmonary dysfunction and shock. Lethal complications following the period of primary shock consisted of fulminant confluent bronchopneumonia, the hyaline membrane syndrome or the onset of desquamative interstitial pneumonia. These changes rendered it difficult to evaluate the effects of the heavy cutaneous scalding on the pathological course of inhalational injuries in those surviving for longer periods.