The Nightmare Summer of 1946: Minnesota’s Deadliest Polio Outbreak

It was a scorching August in 1946 when Minnesota’s hospitals began to look like war zones. The polio virus—then known as infantile paralysis—had crept into the Twin Cities, filling wards with trembling children and terrified parents.

By the time the state’s health officials finally declared a state of emergency, the numbers were already staggering: 2,881 Minnesotans diagnosed, 226 of them dead, the majority under the age of ten. “Those were nightmare days,” recalled pediatrician Stuart Lane Arey half a century later, his voice still tinged with the sorrow of those weeks.

Polio’s early signs were easy to miss. A low‑grade fever, a headache, a sore throat—just enough to be brushed off as a bad cold. Yet for some, the disease progressed in a flash: muscles went limp, breath became a laborious struggle, and iron lungs—those massive metal contraptions—started humming day and night as families clung to a fragile hope.

Back then, nobody really knew how the virus spread. Doctors only knew that summer seemed to make it worse. The University of Minnesota, perched on the edge of the crisis, turned its labs into makeshift battlegrounds, testing vaccines on monkeys while students like Vernon Perrigo examined spinal cords under flickering lights. Dr. Charles Evans, a virologist at the university, told the press that “first we have to learn where the virus comes from; then maybe we can fight it.”

The panic was palpable. Mary Pradt Ziegler, who lost her mother to polio in Wisconsin that same year, wrote in a 1976 essay that “parents were panicky every summer, and kids whined about why they couldn’t go to the beach.” Swimming pools were practically deserted, the State Fair—dubbed the Great Minnesota Get‑Together—was cancelled, and schools announced a two‑week delay to keep the virus at bay.

Hospitals, especially the 65‑bed Sister Kenny Institute in Minneapolis, were overwhelmed. The institute, designed for polio rehabilitation, suddenly housed 180 patients—more than double its capacity. In St. Paul, the Ancker Hospital’s quarantine ward, once a sea of gurneys, was reduced by November to a single eight‑year‑old girl, a sobering image of the epidemic’s slow retreat.

Educators tried to keep learning alive. The University of Minnesota’s radio station, KUOM, broadcast a “School by Air” series, delivering lessons in geography, hygiene, and even cultural awareness to children stuck at home. It was a stop‑gap, a patchwork solution that reminded everyone how fragile normal life had become.

Later outbreaks in the early 1950s would hit more people, but none matched the 1946 death toll. The tide finally turned in 1955 when Jonas Salk’s vaccine rolled out, offering a promise that the nightmare would finally end. By 1956, the happiest story for most parents was the quiet, un‑headline‑making fact that their kids could once again play on the beach without fear.

Today, the 1946 polio epidemic lives on in the stories of survivors who spent years in iron lungs, in the faded photographs of nurses like Margaret Yackel fastening toys to metal machines, and in the collective memory of a state that learned, the hard way, how quickly a silent virus can reshape a community.