1972: Severe weather conditions over the Yucatan peninsula in Mexico begin to converge and form a tropical depression that would become Hurricane Agnes over the next two weeks. This hurricane affected most of the eastern United States with the Northeast being the hardest hit area with heavy rainfall.
1976: A deadly tornado moved across parts of the southwestern Chicago, Illinois suburbs killing three people and injured 23 others. The tornado, with winds over 200 mph moved from Lemont to Downers Grove causing $13 million dollars in damage when 87 homes were destroyed, and another 90 were damaged. The tornado passed over the Argonne National Laboratory, peeling part of a roof of the building housing a nuclear reactor. The tornadoes movement was rather erratic moving southeast to the north and finally turning northwest.
— Simon Brewer (@SimonStormRider) April 20, 201