HOUSTON -

Firefighters responded to a power outage at a hospital in the Houston Heights early Tuesday morning.

The Houston Fire Department says power at the Heights Select Specialty Hospital went out just before 6 a.m. Tuesday.

Officials say four patients on ventilators were transported from the hospital in the 1900 block of Ashland to the Katy Select Specialty Hospital by HFD crews.

Fire officials say they are unsure about what caused the power to go out. However, thousands were without power across the Houston area Tuesday morning after the latest round of winter weather brought cold temperatures, rain, and ice.