BLACKWELL, Okla. (AP) -- Natural gas service has been returned to about half of the more than 4,000 customers in Kay County whose service was interrupted by a pipeline malfunction.

CenterPoint Energy shut off gas service in Blackwell and Tonkawa Tuesday afternoon after a problem at a pipeline regulator station caused pressure to drop.

CenterPoint spokesman Alicia Dixon says all service should be back on by Thursday evening.

The company restored service first to hospitals, nursing homes and schools while the Blackwell Youth Center was used as a shelter for people looking to escape the cold.

CenterPoint says crews are going from gas meter to gas meter to turn the service back on.