SAN ANTONIO (AP) — Authorities say a carbon monoxide leak at a South Texas hotel blamed on a water heater has sent 12 guests to a hospital but all should recover.

The San Antonio Fire Department reports the leak was discovered around 2 a.m. Tuesday as firefighters responded to calls about sick guests at a Comfort Suites Hotel.

Department spokesman Joe Arrington says leaking carbon monoxide was traced to an exhaust pipe that accidentally dislodged from a gas-powered water heater.

Firefighters evacuated more than 100 people from the Comfort Suites Hotel, as a precaution. Arrington says 12 guests taken to a hospital have conditions not believed to be life-threatening.

Fans were used to ventilate the hotel. Arrington says guests were allowed to return several hours later.