... units in multi-unit buildings, • 2.9% of housing units in buildings with 2-4 units, • 5.8% of housing units in buildings with 5-9 units, • 12.1% of housing units in buildings with 10-19 units, ... current version of the U. S. Administration s National Fire Incident Reporting System.1 Wet chemical systems may be coded as dry chemical systems, foam systems, or other special hazard systems and ... apply to this report: Fires excluded from analysis • Fires in buildings with reported structure status of under construction are excluded. No fire protection systems or features can be expected...