The British Empire was suffering in the year 1879. Zulus had massacred a brigade of 1500 soldiers and then the Viceroy in Kabul was butchered by native Afghans, after a mistaken invasion from India. Disraeli, the prime minister, was dying from an incurable disease, and the economy was deeply depressed by competition from Europe and the USA. Then at the very end of the year, the longest bridge in the world collapsed in a storm. The bridge had only been approved by the Government 2 years before, and the public enquiry which followed was the largest ever undertaken. It uncovered a series of design defects, sloppy construction and poor maintenance, and the judges blamed the engineer Sir Thomas Bouch personally. He died within months. This new book reinvestigates the disaster using modern forensic methods, especially the large archive of high quality photographs taken for the enquiry. By enlarging digital images, the author claims to have found evidence for fatigue cracking of a weak part made from cast iron. The pictures also show the many design defects in the metalwork described by the enquiry, but never published before. Some modern engineers blame the high winds that night, but this author speaks firmly for defective design. The shock of the disaster led directly to the magnificent Forth rail bridge, and many other reforms, but the catastrophe remains firmly in the folk memory as an accident-waiting-to-happen.