DALLAS (CBSDFW.COM) – A transformer fire in Dallas has left thousands without electricity.

The fire broke out before 9:00 a.m. at an Oncor transformer just off Central Expressway, near Royal Lane.

The fire has left some 5,000 customers without electricity.

The outages include residential and business properties, including Kindred Hospital Dallas Central; that is currently running off backup generators.

“That’s exactly why critical care customers like that have those types of backups,” Oncor spokeswoman Jamie Molina explained. “We’re trying to figure out how we can get them [Kindred Central] restored first, because we know it’s so important.”

Oncor officials say power is temporarily being rerouted from other sources so customers can get electricity and more importantly air conditioning back.

Workers haven’t determined what caused the transformer to blow.

“We are on the scene trying to investigate what happened, but our first concern is making sure that we can restore power to all of these customers,” Molina said.

Without electricity, there are a number of area intersections that don’t have functioning traffic lights.  Click here to check traffic in the area and find alternate routes.