HERMITAGE (KDKA) — Six people were rushed to the hospital after patrons began passing out at a Golden Corral restaurant in Hermitage, Mercer County, Friday.

There were about 100 people inside at the time when a 6-year-old fainted, then another person and then the restaurant manager.

“It was totally abnormal readings,” said Hermitage Fire Chief Robert Goeltz. “We were way above normal exposure to carbon monoxide.”

Thursday, nine people were sickened by carbon monoxide at an apartment building in Carrick.

“This is how the chamber opens,” said Doctor Raj Adurty of Allegheny General Hospital, who showed KDKA’s David Highfield how they treat people sickened by carbon monoxide in hyperbaric chambers.

The chambers are full of 100 percent oxygen, compared to the 21 percent in the normal atmosphere.

“The goal is to get the carbon monoxide out of the system as fast as possible,” said Dr. Adurty.

Carbon monoxide is a colorless, odorless gas that can be deadly. Dr. Adurty says it can make people sick in a matter of minutes. Faulty furnaces are one possible source.