 Based on its investigation , NIST reiterated several recommendations it had made in its earlier report on the collapse of the Twin Towers , and urged immediate action on a further recommendation : that fire resistance should be evaluated under the assumption that sprinklers are unavailable ; and that the effects of thermal expansion on floor support systems be considered . Recognizing that current building codes are drawn to prevent loss of life rather than building collapse , the main point of NIST 's recommendations was that buildings should not collapse from fire even if sprinklers are unavailable . 
