10 May 1970 – A category F5 tornado strikes Lubbock, Texas destroying about one-quarter of the city. Nineteen of 23 USAF trainers at Lubbock International Airport are destroyed, as well as 100 private planes.
“At 8:10 pm, an off-duty Lubbock police officer spotted a funnel cloud on the east side of the city, and grapefruit-size hail was reported. At 8:15, local radar indicated a hook echo with a strong rotation, prompting a tornado warning to be issued for Lubbock and Crosby counties. The first tornado to strike the city touched down seven miles south of Lubbock Municipal Airport, near the intersection of Quirt Avenue and Broadway. Since it was in a relatively sparsely populated area of the city, this first tornado caused little significant damage; however, reports of damaging hail continued to come in from around the city. At 9:15, tornado sirens in Idalou were sounded, and by 9:30 baseball-sized hail was falling in the northeastern sector of Lubbock.
At about 9:35 pm, a second and much more significant tornado touched down near the campus of Texas Tech University, snapping light poles at Jones Stadium, home of the Red Raider football team, then began to track northeast, carving a path of destruction that at its peak reached almost two miles in width right through the heart of the city. The devastating twister tore through several densely populated residential areas before slicing through downtown, dealing a direct blow to the First National Bank building and the Great Plains Life building. The tornado then moved north toward the airport, where at 10:00 pm, anemometers were already reading winds of 77 knots (approximately 90 miles per hour (140 km/h). At 9:46, the power failed at the Lubbock Civil Defense headquarters, and three minutes later, the local weather bureau lost power and its personnel took shelter from the tornado, which was now bearing down on the area and passed over the Weather Bureau building at 10:03 pm.”
Source: Wikipedia