An occult migrating city gas leak causing significant carbon monoxide poisoning in firefighters

• Published in: Clinical toxicology (Philadelphia, Pa.) Pa.), 2005-05, Vol.43 (5), p.462-462
• Main Authors: Skanning, P G, Soerensen, H S, Mantoni, T, Christophersen, AB
• Format: Article
• Language: English
• ISSN: 1556-3650

15 experienced firefighters from a local fire-station in Copenhagen were brought into the emergency department at 04.00 hours with symptoms of CO poisoning of varying severity. One firefighter had woken up with severe headache, confusion and nausea and managed to call for help before involuntarily urinating and passing out. The fire-station was not on fire and had no gas supply. Despite several missions during the day, the only place common to all poisoned firefighters was their own station. A gas leak had been noted earlier that day but was located 280 m from the station and had been contained by the gas company. On arrival back to the station late at night, one firefighter had noted a faint smell of gas but attributed it to an odour in his clothes from a minor exposure earlier in the day, where the gas smell had been heavy. Initially, due to the location of a governmental office in the proximity, a terror action in the neighbourhood could not be ruled out. A large-scale investigation involving the gas company, police and fire departments was initiated to try to locate the source and evaluate the need for evacuation of the area. >270 flats were investigated. Gas from the earlier leak (high pressure pipes, 2% CO) had formed an underground pocket and due to an up-wards slope of 3%, migrated to the fire-station and entered the building through telecommunication cable-channels. On investigation, gas was found up to 500 m away from the location of the leak. 7/15 firefighters were treated with hyperbaric oxygen and one fire fighter (CO-Hgb 36% on arrival) still suffers sequelae (memory deficits and neurological problems in an upper extremity). The combination of 15 firefighters seeking medical attention in the middle of the night with symptoms of CO poisoning with no known exposure and no civilian casualties, initiated a large-scale investigation that revealed an underground migration of gas over a long distance through wet soil, which eliminated the olfactory warning. The incident has led to the sealing of cable-openings with foam and to the installation of CO detectors in fire-stations.