An examination was made of the events surrounding four deaths caused by excavation cave ins. The first case involved a 53 year old laborer employed by a city sewer department who entered an 11.5 foot deep unshored, vertical walled, manhole excavation to lower and level the area where the manhole foundation was to be set. The second case involved a 22 year old laborer manually digging a dry well and a trench 8 feet deep for a drainage pipe connection. None of the walls were shored or sloped to a safe angle of repose. The third case involved a 45 year old construction man shoveling loose dirt from the bottom of a 21 foot deep unshored, vertical walled excavation to accommodate placement of a fabricated trench shield. The fourth case involved a 32 year old construction field foreman standing in an unshored, vertical walled excavation about 7 feet deep. In light of these accidental deaths, it was recommended that shoring systems or sloping of walls be used in all excavations 5 to 24 feet deep in any type of soil except solid, stable rock; that appropriate shoring, shielding, or sloping requirements for all excavations deeper than 24 feet be determined by an engineer qualified to make these determinations; and that all employers engaged in excavation activities familiarize themselves with the provisions of the National Bureau of Standards NBS/NIOSH document, Development of Draft Constriction Safety Standards for Excavations, and implement them as safe work practices in addition to compliance with existing OSHA standards.