A teenager was killed and his brother was critically injured when they were overcome by fumes in a tunnel at the recycling plant where they worked, Kern County officials said Friday. Armando Ramirez, 16, died and his brother, Eladio Ramirez, 22, was severely injured in the accident Wednesday, said Sean Collins, spokesman for the Kern County Fire Department. Eladio Ramirez was hospitalized at Kern Medical Center in critical condition, Collins said. A third man, who tried to help the brothers, was treated and released, Collins said. That man never entered the tunnel. Firefighters said they found the brothers unconscious about 7 feet down a shaft in the cement drainage tunnel at the plant in Lamont, just southeast of Bakersfield. A rescuer using breathing equipment put them in harnesses so they could be brought to the surface. Tests showed high concentrations of hydrogen sulfide in the tunnel. The gas, released during composting, can damage the brain and central nervous system. The California Division of Occupational Safety and Health launched an investigation. The U.S. Department of Labor also was investigating because of the age of the victim. A spokesman for the plant's operator, Community Recycling and Resource Co., based in Sun Valley, did not return a telephone message Friday. The brothers, who lived in Arvin, were given only painters' masks and rubber boots to protect themselves from the fumes, relatives told The Bakersfield Californian (http://bit.ly/nrvXK9). "Why don't they take precautions if they know it's dangerous?" asked Fidencio Corminales, a relative. "They don't give them the right equipment. It upsets me." The brothers came to the United States from the southern Mexican state of Oaxaca about two years ago, relatives said. They initially went to Salinas, where their mother works harvesting produce, they said. Eladio got a job in the fields but Armando did not because he was too young, the Californian said. Then they moved to Arvin to live with other relatives, said Veronica Garcia, an aunt. Armando got a job with the recycling company first, then Eladio joined him. "They were good people," Garcia said. Neither brother talked about danger on the job, but they did speak of a strong odor, Garcia said. Cal-OSHA spokeswoman Erika Monterroza said the company had no record of workplace violations. There had been a few land use rule violations in the past, the Californian reported, citing a county official. Kern County Environmental Health spokesman Brian Pitts told KBAK-TV that the plant takes green waste and food waste from around the state and turns it into compost that is sold for things like residential and commercial landscaping. It's not clear how hydrogen sulfide got into the shaft and drain, Pitts said, but it is highly toxic. "At certain concentrations, you get a whiff of it, and you can't smell anymore," he said. That is serious, he said, because it's not being detected but it's still doing damage.