GRIM ANALYSIS Members of London's emergency services in the Grenfell Tower apartment block in June, three days after a fire killed at least 80 people. The fire's severity was blamed in part on the building's combustible exterior wall assembly, a component of modern construction that is found on buildings worldwide. (AP/WIDE WORLD) N F PA . O R G / J O U R N A L * NFPA JOURNAL | 37http://nfpa.org/journal