Rescue crews in Fort Worth evacuated a nail salon for a short time on Wednesday night after more than a dozen people reported feeling ill.
The call for help was made at around 4 p.m. on Wednesday where people inside the Venus Nails Spa along the 4800 block of Overton Ridge Boulevard reported feeling sick.
Firefighters tested the air and found high levels of carbon monoxide. The fire department said the leak came from a faulty water heater.
"It was hectic. A lot of people were coming out. No one was coming in after the fire trucks came," said Matt Greason, who works nearby.
Rescuers treated 13 people at the scene and took one additional person to the hospital.
Fort Worth Fire says Atmos responded to the scene and shut off the natural gas to the business. No other businesses in the shopping center were impacted. As a precaution, firefighters tested nearby shops but did not find elevated levels of CO.
Officials with MedStar told NBC 5 this is the second sick call at the same address today. Earlier on Wednesday, crews found someone passed out inside the business and they also were transported to the hospital. The fire department says it did not test carbon monoxide levels on the first call.
Editors note: Initial reports from the Fort Worth Fire Department indicated that 20 people were being evaluated, but that number has since decreased to 15.