The bowstring truss is neither the most common type of truss nor the type most likely to kill firefighters. Trusses of any age or design have common characteristics: http://buildbuild.hostoi.com
they use the least amount of material to achieve the greatest strength for long spansthey have a smaller cross-section and considerably less mass than a solid beam of the same strength, resulting in less inherent fire resistance and early failure in firesfailure of a single connection can cause the failure of the entire trussfailure of either the top chord or bottom chord can cause the failure of the entire truss
