Substation Near Denver Hospital Explodes, Patients Being Evacuated

06/08/2010 08:32 am ET | Updated May 25, 2011

DENVER — Power has been restored to Denver residents following a transformer fire, but customers are being urged to conserve electricity over the coming days.

Nearly 31,000 customers lost power Monday evening after a substation caught fire.

Xcel Energy says power may have to be shut off to some customers for up to an hour at a time as crews repair the substation.

Xcel hasn't determined what caused the explosion and fire, which came on the city's hottest day of the year so far. The temperature hit 94 degrees.