The caldera collapsed most recently sometime between 410 and 535 AD ( based on radiocarbon dating of plant life directly related to the eruption ) , which produced widespread pyroclastic flows and devastated Mayan cities . The eruption produced about of tephra ( several times as much as the 1980 eruption of Mount St. Helens ) , thus rating a 6 on the ( VEI ) Volcanic Explosivity Index . The " ash-cloud fallout . . blanketed an area of at least 10,000 square kilometers waist-deep in pumice and ash " , which would have stopped all agricultural endeavor in the area for decades . It is also theorized that the eruption and subsequent weather events and agricultural failures directly led to the abandonment of Teotihuacan by the original inhabitants . There is an opinion that this eruption caused the extreme weather events of 535 – 536 in Europe . <!-- (The following was located here in the eruption history) One of the most prominent tourist destinations is a town called Apulo, which was one of the towns affected by the 2009 floods and mudslides caused by Hurricane Ida. --> Later eruptions formed several lava domes within the lake and near its shore . The only historical eruption , which occurred from December 31 , 1879 , up to March 26 , 1880 , produced a lava dome and had a VEI of 3 . The lava dome reached the surface of the lake , forming the islets known as Islas Quemadas
1980 eruption of Mount St. Helens
1980 eruption of Mount St. Helens
Lake Ilopango