2011 Joplin tornado
The tornado initially touched down just east of the Missouri-Kansas state line near the end of 32nd Street at 5:34 pm CDT (22:34 UTC) and tracked due east, downing a few trees at EF0 intensity. Eyewitnesses and storm chasers reported multiple vortices rotating around the parent circulation in that area. Civil defense sirens sounded in Joplin 20 minutes before the tornado struck in response to a tornado warning issued by the National Weather Service, but many Joplin residents didn't heed them. The tornado strengthened to EF1 intensity as it continued through rural areas towards Joplin, snapping trees and power poles and damaging outbuildings. Widening, the tornado then tracked into the more densely populated southwest corner of the city near the Twin Hills Country Club. It heavily damaged several homes at a subdivision in this area at EF1 to EF2 strength. The tornado continued to strengthen as it ripped through another subdivision just east of Iron Gates Rd. Numerous homes were destroyed at EF2 to EF3 strength at that location, and multiple vehicles were tossed around, some of which were thrown on or rolled into homes.
The now massive wedge tornado then crossed S. Schifferdecker Ave., producing its first area of EF4 damage as several small but well-built commercial buildings were flattened. Consistent EF4 to EF5 damage was noted east of S Schifferdecker Ave and continued through most of southern Joplin. Numerous homes, businesses, and medical buildings were flattened in this area, with concrete walls collapsed and crushed into the foundations. A large steel-reinforced step and floor structure leading to a completely destroyed medical building was "deflected upward several inches and cracked". Steel trusses from some of the buildings were "rolled up like paper", and deformation/twisting of the main support beams was noted. Multiple vehicles were thrown and mangled or wrapped around trees nearby. Several 300-pound concrete parking stops anchored with rebar were torn from a parking lot in this area and were thrown up to 60 yards away. Iowa State University wind engineer Parka Sarkar was able to calculate the force needed to remove the parking stops and found that winds exceeding 200 mph were needed to tear them from the parking lot.
Tornadoes of 1974
The 1974 Super Outbreak was one of the destructive tornado outbreaks ever known in United States history. Many notable tornadoes occurred, such as the Xenia, Ohio tornado which was an F5 tornado that killed 34 people and destroyed a large portion of the town. The Xenia tornado was so strong and the damage so severe, that Dr. Fujita considered rating it an F-6, although the scale only went to F-5. He decided not to since some of the damage that would indicate that it could be the mythical F-6, might have been due to the structure not being as strong as it should in the first place. One of the 30 violent tornadoes, and F4 striking Monticello, Indiana, produced the longest damage path recorded during the 1974 Super Outbreak, on a southwest to northeast path that nearly crossed the entire state of Indiana. According to most records, this tornado formed near Otterbein in Benton County in west central Indiana to Noble County just northwest of Fort Wayne - a total distance of about 121 miles (195 km). Much of the town was destroyed including the courthouse, some churches and cemeteries, 40 businesses and numerous homes as well as three schools. It also heavily damaged the Penn Central bridge over the Tippecanoe River. Overall damage according to the NOAA was estimated at about US$250 million with US$100 million damage in Monticello alone. The Monticello tornado caused 18 deaths. One of the seven F5 tornadoes, the Huntsville, Alabama tornado, took a similar path of the tornado that struck Huntsville on April 1. A large, F4 tornado struck Louisville, killing 3 people and demolished most of Audubon Elementary School and affected the neighborhoods of Audubon, Cherokee Triangle, Cherokee-Seneca, Crescent Hill, Indian Hills, Northfield, Rolling Fields, and Tyler Park. The fast-moving nighttime tornado that devastated the town of Guin, was the longest-duration F5 tornado recorded in the outbreak and considered to be one of the most violent ever recorded. The Guin Tornado traveled over to just west of Huntsville before lifting just after 10:30 pm CDT. It formed at around 8:50 pm CDT near the Mississippi-Alabama border, striking the Monterey Trailer Park, resulting in major damage at that location. The tornado then became extremely violent as it approached and entered Guin, with multiple areas of F5 damage noted in and around town. The tornado first struck the Guin Mobile Home Plant as it entered the town, completely obliterating the structure. Nothing was left of the plant but a pile of mangled steel beams. The town's downtown area was also heavily damaged, with many businesses and two churches completely destroyed. Residential areas in Guin suffered total devastation, with many homes swept completely away and scattered across fields. There were at least 148 tornadoes in the tornado outbreak and 318 fatalities, a record that was beat by the 2011 Super Outbreak.