McKINNEY — On May 15, 2013, winds up to 165 mph from an EF-4 tornado ripped through Granbury.
Six people were killed; about 100 homes were destroyed, including 58 built by Habitat for Humanity.
The damage to the Habitat homes in the Rancho Brazos subdivision forced the organization to look at new ways to protect the families they help.
"We looked at the devastation in Granbury and thought, 'How can we make our houses stronger?" said Wilson Fryar, construction director for North Collin County Habitat for Humanity.
North Collin Habitat volunteers are now building their first-ever "tornado-proof" home in McKinney. A local company donated metal clips and ties to shore up the house, which is built to endure 120 mph winds or an EF-1 twister.
The posts in front of the house have all been fitted with steel straps. The straps are actually set 10 inches deep into the concrete when the foundation is poured.
"If this post goes, the slab's going with it," Fryar said.
Steel ties will better secure the roof and walls, the front porch, overhangs, gables and the car port in the event of a tornado. But what happens when an EF-4 tornado, like the one in Granbury, touches down?
"Those storms have higher wind," said Billy Viars of Strong-Tie, the company donating materials to shore up the Habitat homes. "But their path is very, very narrow. So within a neighborhood street, you may have an EF-4 or an EF-5 tornado, but those wind speeds may only exist at two or three homes."
Nine out of every 10 tornadoes are rated EF-1. Habitat officials say their latest efforts will better protect the families they serve from weather-related disasters.