At about 13:00 on 18 March 1925 a tornado touched down near Ellington, Missouri. It would not lift for approximately three and a half hours, tracking northeast in a nearly straight line across Missouri, southern Illinois, and Indiana — a damage path of some 350 kilometres, the longest ever reliably recorded for a single tornado.
Nothing about it looked like the tornado of the popular imagination. Moving at up to 30 metres per second — highway speed — and shrouded in rain and a rolling boil of low cloud, it presented as a black fog on the horizon rather than a funnel. Towns had minutes or seconds between recognition and impact. Many residents, veterans of ordinary storms, realised what it was only when buildings began to come apart.
The path
The worst of it fell on the coal towns of southern Illinois. Gorham was essentially erased. At Murphysboro the tornado killed 234 people — still the highest toll of any single town from a tornado in American history — and fires from wrecked stoves burned trapped survivors in the rubble. De Soto lost 69, including 33 children when its school collapsed, the deadliest school tornado strike on record. West Frankfort’s miners came up from underground to find their surface town gone and their families among the dead. In Indiana, the town of Griffin was flattened before the storm finally dissipated near Petersburg.
The final count: 695 dead, more than 2,000 injured, some 15,000 homes destroyed. It remains the deadliest tornado in United States history by a wide margin.
The forbidden word
No warning had been possible — and not only for lack of science. The US Weather Bureau had for decades banned the word “tornado” from public forecasts, on the doctrine that the panic caused by a prediction would do more harm than the storm. The 1925 forecast for the region promised “rains and strong shifting winds.”
The ban outlived even this disaster; it eroded only in the 1930s and was decisively abandoned after 1948, when two Air Force officers at Tinker Field issued the first successful tornado forecast. The modern machinery of watches, warnings, sirens, and radar owes its existence to the argument the Tri-State Tornado settled: that people die not from fear of a warning, but from the absence of one.
Meteorologists still debate whether the 1925 track was one continuous tornado or a family from a single supercell; a major reanalysis in 2013 upheld most of the continuous path. Either way, no storm since has approached its toll — a record everyone in the field hopes is permanent.