In the early 1960s a number of sizable explosions and fires occurred in the oil and petrochemical industries. A light hydrocarbons plant in Louisiana suffered a vapor cloud explosion. This phenomenon, although it had occurred before, was largely unrecognized in industry. At about the same time, the process industries were moving toward the "jumbo" plants. Formerly, ammonia was produced in multiple plants of 100 to 300 tons/day capacity with multiple parallel lines of reciprocating compressors. However, in the early 1960s ammonia plants having capacities of 750, 1000, and 1500 tons/day with centrifugal machines were rolling off the designers boards. Large, single-train olefin plants, with capacities of 1.5 billion pounds per year, were also being designed and erected. As a response to these trends, a number of people from industry and insurance put together a symposium to explore ways to improve loss prevention in the process industries. This symposium contained six sessions and was held at the AIChE National meeting in Houston in 1967. Attendance was excellent and a committee was formed to prepare annual symposia on the topic. These symposia are still held at AIChE National meetings with the 40th Loss Prevention Symposium being held this year. This paper will discuss some of the highlights of these symposia and some of the people that have made them so successful over the years. (C) 2006 American Institute of Chemical Engineers.