However, the fire bombs used in the air raids were weapons which caught fire after penetrating roofs, so in cases where the firebombs directly hit the roof, there were many examples in which the outer walls remained intact, while the inside was burnt out.
ただし空襲で使用された焼夷弾とは屋根を貫通したあと内部で発火する兵器のため、屋根に焼夷弾が直撃した場合は、外壁は無事でも内部が焼け落ちたという例も多い。