Amazon announced its intent to open two new fulfillment facilities in Edwardsville, Illinois, on June 2, 2016. Each facility would cover , with one focusing on larger items and the other on smaller items. This was predicted to contribute to the creation of 1,000 full-time jobs for the region, which Mayor of Edwardsville Hal Patton described as a "much-needed employment opportunity" for the area. The facility was located in the Lakeview Commerce Center, a
Greater St. Louis commercial development site brokered by
CBRE Group off of
Illinois Route 111 near the
I-270/
I-255 interchange east of
downtown St. Louis, which also hosted facilities for J.F. Electric,
Spectrum Brands, and
World Wide Technology by 2020. The Amazon facilities opened in August 2017, with the building focusing on larger items referred to as STL4 and the one for smaller items as STL6. One year later, in August 2017, the first public tour of STL4 was given to news media, "members of the community", and to federal-level politicians
Dick Durbin (Democratic senator from Illinois) and
John Shimkus (Republican representative from
Illinois's 15th congressional district). At the time, both facilities combined had over 2,000 employees, over twice as much as projections made the year prior. In 2018, Contegra Construction constructed the shell of the DLI4 building at the corporate complex, which would become an Amazon delivery warehouse. At DLI4's completion in September 2020, the warehouse took up a total of , of which was office space. DLI4 was designed by architectural firm Richard L. Bowen & Associates. Throughout December 2021, ahead of the
Christmas holiday, Amazon's DLI4 site had around 190 employees across all shifts, according to a spokesperson. A majority of the workforce employed at the site were contracted delivery drivers, and expected demand from the holiday prompted the company to increase the number of these contractors. Having fewer full-time delivery workers was part of an initiative at Amazon starting in 2018 to reduce the company's reliance on external carrier services. Only seven full-time employees were at DLI4 at the time of the tornado.
Initial severe weather forecasts Forecasters at the
National Weather Service office in St. Louis, Missouri were tracking a potential severe weather event across parts of Missouri and southern Illinois. A forecast discussion on the afternoon of December 9 outlined that Friday, December 10, would be warm across the region, as a low-pressure system ejecting from the Rocky Mountains would bring in anomalously high dew points and temperatures that, in areas southeast of St. Louis, were forecasted to potentially exceed , in places where low-level cloud cover could dissipate earlier in the day. The system was forecasted to move through the St. Louis office's area of responsibility in the time frame between 02Z and 09Z Saturday, or between 8p.m. Friday through and 3a.m. Saturday,
Central Standard Time. Confidence also existed that storms produced by the system could produce tornadoes, and would be moving very quickly. Forecasters at the
Storm Prediction Center in
Norman, Oklahoma, were expecting a severe weather event to occur on the evening of December 10. An enhanced risk, the third highest risk the agency issues, was outlined across much of the middle
Mississippi River valley shortly before midnight on the 9th. This included St. Louis and surrounding areas, with risks outlined for damaging wind, large hail, and tornadoes. At this time, it was expected that storms across Missouri were going to form after sunset, and would evolve into a
squall line, potentially limiting the threat of
supercell tornadoes, except for those forming ahead of the line earlier in the evening. It was also noted that, at the time, the HREF
forecast model was inconsistent on the location and timing of where storms would form initially. By the 10th's 1630Z outlook, outlined at 5:08p.m.
Central Daylight Time, the St. Louis area remained under an enhanced risk; however, a moderate risk, the second-highest risk applicable, was introduced further south. Confidence was strong that sufficient atmospheric conditions would produce strong tornadoes throughout the day across parts of the middle Mississippi and lower
Ohio River valleys.
Onset of severe weather At 5:20p.m., forecasters at the Storm Prediction Center issued a
tornado watch for much of Missouri and parts of Illinois, including
Madison County. This watch was effective until 11:00p.m. that night. Seven minutes later, in a mesoscale discussion, forecasters discussed the conditions over the region in greater detail. By this time, storms recently initiated over southwestern Missouri, in the vicinity of
Springfield. As atmospheric conditions across the region degraded later on that evening, the threat for severe weather would increase. This discussion specifically outlined an area of eastern Missouri where it was expected that mature storms could interact with an area of supporting atmospheric conditions, producing the region's "best chance for tornadoes". At 7:02p.m., another such discussion detailed how a line of storms was present over central Missouri, some exhibiting features of embedded supercell thunderstorms. One of these storms, with the coldest
cloud tops of the line, was directly heading towards St. Louis. This storm was outlined as responsible for an elevated threat of tornadoes and other severe weather, given atmospheric parameters at the time. That evening, multiple strong tornadoes struck the St. Louis National Weather Service office's area of responsibility. Of these, three were caused by a single supercell. The first of these, rated EF3, touched down at 7:35p.m. and caused significant damage in
Defiance, Missouri. Before it lifted at 8:01p.m. west of
Bridgeton, Missouri, this tornado resulted in 1 death and two injuries. Five minutes later, at 8:06p.m., a
tornado warning was issued for Edwardsville and surrounding areas, as forecasters tracked what was believed to be an ongoing tornado in
Bridgeton, Missouri. As weather conditions began to worsen across the Edwardsville area, one contractor for Boxify Logistics stated that some delivery drivers were told to park in a designated area or return home, with others being instructed to return to DLI4. Another delivery worker recalls talking to dispatcher Kevin Dickey, who would die in the tornado, who asked them to check on weather conditions in surrounding areas, before telling them to "get home safe". At 8:06p.m. and again at 8:16p.m., the Edwardsville Amazon facilities would receive notice of imminent severe weather through a web application. When the warning was received by DLI4's manager, they alongside an assistant began traversing the warehouse on foot to let other workers know about the storm, and to gather at the site's northern bathroom, which was the site's designated shelter for severe weather. The tornado that would strike the DLI4 warehouse, which was spawned by the same parent supercell thunderstorm as the EF3 tornado in Defiance, Missouri, first touched down to the west of the I-270/I-255 interchange at 8:27p.m. == Collapse ==