The roof trusses were secured at each of the outside, and load bearing walls, with something calls a hurricane clip.The purpose of the hurricane clip is as the name suggests to hold the roof down in a big wind. The trusses could actually be toe-nailed in place, and hence not move around. However, this is not sufficient when the wind blows...
The uplift under the eaves during strong wind could be strong enough to rip off the roof.