The glass, bricks, and block that make up these walls will be blown into the interior of the building. The winds tend to pull these sides outward. The pressures here are much smaller than on the windward side. The net result is therefore less damage to the leeward walls. The windows on these walls usually blow out.
Severe damage can occur to the leeward walls if the windward walls are penetrated.
Overhangs, and eaves on the windward side are the most vulnerable, and compound the uplift problem. Roofs with steep slopes are somewhat less vulnerable to up life, but can be blown sideways. Lightweight roofing materials, such as gravel, wood, insulation, shingles, and steel deck, often are lifted and thrown hundreds of feet in all directions by tornadoes. The weight of concrete roofs tends to resist uplift. The high-speed whirling winds of a tornado can turn almost anything or anyone into a missile.