Em 1937, na epidemia de pólio, crianças tiveram aulas pelo rádio

https://www.washingtonpost.com/education/2020/04/03/chicago-schools-closed-during-1937-polio-epidemic-kids-learned-home-over-radio/

This post tells the story of what happened in 1937 when the public schools in Chicago closed for three weeks, delaying the start of the school year, because of fears about the spread of polio, which caused epidemics over several decades. Some 457,088 people got polio from 1937 to 1997, according to Post-Polio Health International. Thousands of people, including children, died and many more were paralyzed.