More than 10,000 Oncor customers spent another night in the dark as recovery crews work around the clock to restore power to the areas affected most by Sunday night's tornado outbreak.

A total of nine tornadoes are confirmed to have touched down in North Texas Sunday, the strongest being an EF-3 that brought 140 mph winds to North Dallas.

Stella Ballard

Oncor reported 10,800 electricity customers in Dallas County were without electricity as of 2:30 a.m. Wednesday. More than 500 Collin County customers had no power, along with smaller pockets of outages in Tarrant and Rockwall counties.

The Dallas ISD canceled Wednesday classes at the following campuses due to power outages:

• Cary Midlde School

• Dealey Montessori

• Franklin Midlde School

• Hillcrest High School

• Kramer Elementary School

• Jose "Joe" May Elementary School

• Francisco Medrano Middle School

On Monday, Superintendent Michael Hinojosa said two campuses — Walnut Hill Elementary School and Cary Middle School — are a total loss and will need to be rebuilt.

Classes are canceled Wednesday at several Dallas ISD campuses due to extensive storm damage and ongoing power outages.

Another cold front is expected to bring another wave of rain this week, putting people with damaged property against the clock to save their valuables from further destruction.

With thunderstorms in the forecast Thursday, people cleaning up Sunday's tornado damage are working against the clock before rain does additional harm.

The city of Garland estimates about 175 homes and businesses were damage in an EF-2 twister, which brought maximum sustained winds of 135 mph. At least 36 of those buildings had major damage or were destroyed.

Property damage is estimated at $17 million, a city news release said.

The city of Dallas said Tuesday firefighters had inspected 68% of damaged buildings. Dallas Fire-Rescue reported 67 buildings were destroyed, 202 had major damage and 175 with minor damage.

The city said crews were working to fix 139 traffic signals, with 40 of those needing to be rebuilt.

Teachers from tornado-ravaged Thomas Jefferson High School in Dallas fanned out in the neighborhood Tuesday to reassure students that classes would resume.

A voluntary curfew remains in effect at least through Thursday in Dallas in the areas most damaged. Residents are asked to stay indoors from 7 p.m. to 7 a.m.

The Dallas North Tollway northbound exit to Royal Lane remained closed Wednesday morning due to storm damage.

In Garland, portions of Shiloh Road have been closed due to power transmission line repairs. The road is expected to reopen Wednesday, the city said.

Video provided to NBC 5 by Oncor, shows crews working to restore power after severe storms hit North Texas on Sunday night.

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