San Marcos fire officials say two incidents of carbon monoxide exposure have killed one worker and hospitalized another.
Fire Marshal Ken Bell says the separate incidents happened within a 12-hour period spanning Tuesday and Wednesday.
Fifty-seven-year-old Rob Schmid died about 15 feet below ground late Tuesday afternoon in a chamber at a state-run fish hatchery.
He was exposed to the gas while working on an underground pump. Bell says the colorless, odorless gas was at five times the limit that humans can handle.
The second incident happened early Wednesday morning at a private construction site across town.
Bell says a worker was operating a machine in a confined space. The unnamed worker is being treated in a hypobaric chamber at an area hospital.
