A NIOSH investigation of a fatal accident caused by insufficient oxygen in a Georgia sewer was reported. A plumbing contractor descended into a sewer manhole in the middle of the street to measure the length of a sewer line snub. He had not tested the atmosphere or ventilated the sewer vault before entry, nor did his company have a written safety program or confined space entry procedures. After complaining of a strong odor, he lost consciousness. Attempts at rescue by two coworkers were unsuccessful as they became dizzy; thus, emergency rescue personnel were not notified until about 20 minutes after the accident. The victim died of asphyxia due to oxygen deficiency in an atmosphere containing 20 percent methane (74828) and 6 percent oxygen. NIOSH Division of Safety Research personnel conducted a site visit and investigation of the accident as part of the Fatal Accident Circumstances and Epidemiology Project. The contractor was under subcontract to another company, which also had no confined space entry procedures. NIOSH recommendations were that employers initiate comprehensive policies and procedures for confined space entry, to include: air quality testing; monitoring of the space to determine that a safe oxygen level is maintained; employee and supervisory training in confined space entry and use of respiratory protection; emergency rescue procedures; and availability, storage, and maintenance of emergency rescue equipment.