DENVER — Multiple Denver metro agencies reported receiving several 911 calls on Sunday morning concerning the smell of natural gas or sewage.
"Aurora Fire Rescue is aware of a natural gas or sewage odor prevalent across the Denver metro area this morning," read a tweet from Aurora Fire Rescue.
South Metro Fire suggested the smell could be the result of temperature inversion.
"Temperature inversions can trap odors and are often to blame on cold mornings. Meters sometimes burp gas to regulate pressure and the mercaptan odor lingers," South Metro Fire wrote in a tweet.
Mercaptan is often added to natural gas to make it easier to detect.
Temperatures were below zero overnight in the Denver metro area and will remain dangerously low throughout the day Sunday.
