The PEMEX LPG (Liquefied Propane Gas) Terminal, of 16,000 m3 capacity, in San Juan Ixhuatepec in the outskirts of Mexico City, was regularly supplied by 3 refineries. At 5:35 am of November 19,1984 , the control room noticed a pressure drop in the pumping station, without however being able to find its cause. An 8-in diameter pipeline between a spherical storage tank and a group of cylindrical vessels was leaking. The leak lasted between 510min, while a 0.4m/s wind was in the area. A large vapor cloud was formed, followed by a VCE. The resulting casualties included 550 deaths and more than 6,400 wounded. Material damages were estimated at $34,000,000 (in 2005 prices). The facilities dated from 1961-1962 and thus had already been in operation for 20 years. During this time, the area surrounding the terminal was inhabited, and there were houses within a distance of 130m. The terminal's capacity was 16,000 m3(29,760kg), and it is estimated that about 4,750 kg of propane leaked and evaporated into the atmosphere. Use TNT and TNO methods and calculate the overpressure at distances of 25,75,125 and 200m, and draw the overpressure curve as a function of the distance from the center of the explosion. The following data are available: Heat of combustion of propane, Hc=46,010kJ/kg Heat of combustion of TNT, HTNT=4,760kJ/kg Volume of the whole cloud =63,884m3 Efficiency of explosion =5%