Seven people were rushed to the hospital Monday afternoon for treatment of suspected carbon monoxide poisoning.

Firefighters were called to the 1400 block of N. 10th St. in Reading around noon on Monday.

They found high levels of the gas in six attached homes on the block, including one that measured above 200 parts per million.

The average level for a home without a gas stove varies from 0.5 to 5 parts per million, according to the Environmental Protection Agency. Levels near properly adjusted gas stoves are often five to 15 ppm.

Two adults and five children were experiencing symptoms of carbon monoxide poisoning and were taken to the hospital.

Fire crews on the scene said they pinpointed the source of the gas to a blocked chimney that is shared by two of the homes.

Close to 200 people die each year as a result of carbon monoxide poisoning, according to the U.S. Consumer Product Safety Commission.