Heavy Ground: William Mulholland and the St. Francis Dam Disaster. Western Histories Series. By Norris Hundley Jr. and Donald C. Jackson. (Oakland: University of California Press, 2015. viii + 440 pp. Illustrations, maps, appendices, notes, index. $55.00, £37.95). On March 12, 1928, the St. Francis Dam in the Santa Clara River Valley north of Los Angeles collapsed with 12 billion gallons of water creating a tsunami of death and destruction on its way to the Pacific Ocean. The flood killed an estimated 400-450 people and devastated the landscape. Except for the pioneering work of Charles Outland, few historians have conducted in-depth research into the causes and consequences of this tragedy. In recent years it has at last attracted scholarly attention, with studies by J. David Rogers and Jon … hoffmanaz{at}gmail.com