US Lightning Bolt Leaps Into Record Books at 768 Kilometers LongA single lightning bolt that leapt across three U.S. states has been identified as the longest ever, the U.N. weather agency said Tuesday. Dubbed a megaflash, the rare low-rate horizontal discharge covered 768 kilometers (477 miles) between clouds in Texas and Mississippi in April 2020. It was detected by scientists using satellite technology and its distance - beating the previous record by 60 kilometer - confirmed by a World Meteorological Organization committee. "That trip by air[plane] would take a couple of hours and in this case the distance was covered in a matter of seconds," WMO spokesperson Clare Nullis said. Another megaflash that occurred above Uruguay and Argentina in June 2020 also set a record, as the longest-lasting at 17.1 seconds, the WMO said. While these two newly cataloged megaflashes never touched the ground, they serve as a reminder of the dangers of a weather phenomenon that kill hundreds of people a year. "We reiterate our message: when thunder roars, when you see lightning — go indoors. Don’t seek shelter in a beach hut, don't stand under a tree," Nullis said.