Forecasters say the tornado that claimed six lives and destroyed dozens of homes in North Texas is believed to have had winds up to 200 mph.
The National Weather Service said the preliminary storm estimate for Wednesday night's tornado in Granbury was an EF-4, based on the Fujita tornado damage scale. That means the storm carried wind speeds of 166 mph to 200 mph.
The NWS believes 10 tornadoes raked North Texas in a violent system, including the one in Granbury, about 40 miles southwest of Fort Worth. Other tornadoes damaged nearby Cleburne and Millsap.
Forecast Jesse Moore says NWS teams traveled to the affected cities Thursday to survey the damage and speak with emergency management officials.
He says more than one tornado might have touched down in various areas.
Official: Tornado left 'total devastation'
Hood County Commissioner Steve Berry said Thursday he couldn't tell one street from another in an area of Granbury where homes were ripped from foundations and others turned to rubble.
In the Rancho Brazos subdivision, debris is hanging from utility lines as dozens of law enforcement officers patrol the area to restrict access and guard the scene.
Half of one home was torn away while the other half remains standing, with glasses and vases remaining intact on shelves.
Berry says the overnight tornado caused "total devastation" in the neighborhood. The area is about 40 miles southwest of Fort Worth.
Thousands lose power after deadly Texas tornadoes
Utility officials say nearly 3,500 homes and businesses remained without power 24 hours after a North Texas tornado outbreak left at least six people dead.
Dallas-based Oncor on Thursday had almost 3,100 customers without power as crews worked to restore service.
United Cooperative Services reported 400 outages remained Thursday. United Cooperative Services says more than 100 utility poles were toppled by the severe weather.
Perry says Texas monitoring tornado recovery
Meanwhile, Texas leaders have offered concern and support to communities raked by the tornadoes.
Gov. Rick Perry on Thursday said he's deeply saddened by the deaths. Perry says the State Operations Center continues to monitor the situation.
Forecasters say tornadoes that were part of the same storm system hit nearby Cleburne and Millsap.
U.S. Sen. John Cornyn also offered condolences over the destruction and loss of life. Cornyn says all of Texas stands with the communities.
Shelters welcome Texas tornado-displaced residents
Two churches in a North Texas city where a massive tornado killed six people have opened their doors as Red Cross shelters.
First Christian Church and First United Methodist Church -- both in Granbury -- were available Thursday to assist victims.
First Christian Church Associate Pastor Tiff Williams says about 20 people spent Wednesday night at the church during the violent weather.