Roughly 1,700 EPB customers are without power tonight, according to EPB spokesman John Pless.
Pless said much of the outage is centered around the Highland Park and Ridgedale areas in midtown Chattanooga.
The outage was first reported just after 9 p.m. when a line of thunderstorms moved into the area.
Pless said he couldn't confirm the cause of the outage, but he believed the heavy rains were a factor.
"It appears to be a weather event," he said. "But we're still in investigation mode."
Pless said the company's main 46 kilovolt distribution center, the arterial lines that distribute power throughout the city, was down but that the automated system managed to restore power to those lines and the thousands of customers they serve fairly quickly.
Additional crews have been dispatched to assess the damage and restore power to those still affected as quickly as possible, Pless said.