On February 11, 2018, at 1:15 p.m. Pacific standard time, a release of compressed hydrogen and subsequent fire occurred during the transportation of an Air Products and Chemicals, Inc. 2014 Mack CXU613 truck tractor in combination with a 2015 Cheetah Chassis Corporation chassis, with a mounted CT-250 tube trailer module. The tube trailer module contained 25 non-US Department of Transportation specification fully wrapped carbon fiber reinforced aluminum-lined cylinders, 24 of which were fully loaded with 240 kilograms of compressed hydrogen.1 The module caught fire on Golden Springs Drive in Diamond Bar, California. Pressure relief devices, which actuated on 12 of the cylinders, released about 120 kilograms of hydrogen that was likely consumed in the fire. The Los Angeles County Fire Department estimated about 1,400 to 2,000 people were evacuated from the adjacent business district and a nearby residential area. Equipment damages were estimated at $175,000.