Abstract: At approximately 3:30 p.m. on February 16, 1993, Employee #1, his supervisor, and a coworker went to the Warner Oaks Apartment Complex in response to complaints from the maintenance person about boilers not working. Upon arriving at boiler #1 (a tankless water heater boiler with electronic ignition pilot and electronic circulating pump), the supervisor told Employee #1 to check the line for air. Employee #1 closed the gas valve, opened the union at the boiler, and reopened the valve. He found that there was no gas pressure and the supervisor concurred. The supervisor and a coworker went to boiler #3 near parking space #104 and did the same, in addition to first turning off all electrical switches. The supervisor found no gas pressure, and told the coworker to check the main gas valve. The coworker found it partially open and turned it all the way open. The supervisor said he heard and smelled gas come through the line so he closed the valve and reconnected the union at boiler #3. Employee #1 said that he did not hear or smell gas until just before a fire was ignited and flames shot up, and he jumped back. He then tried to reach and close the valve, but was unable to because of the heat and flames. Employee #1 was hospitalized for 10 days with third-degree burns on his wrist, neck, and the left side of his face; and second-degree burns on his lips and the right side of his face.