"Trouble really starts at 60 mph, or Level 10 on the 200-year-old Beaufort wind scale, developed by a British admiral to estimate wind speeds before the invention of instruments to measure it. “You can get windows blown out,” Elsner said, and parts of roofs may fly off.
Above 75 mph, the situation is dire. “You can get some full-scale compromises of buildings,” Elsner said.
If buildings break apart, airborne debris becomes a problem. Shingles, glass and nail-riddled wall studs can all start flying around. And the wind will whip even faster through tight areas, such as the tunnel-like alleys between two houses built within spitting distance...."