On the afternoon of Thursday, May 21, 1953, a violent F4 tornado struck the cities of Port Huron, Michigan, United States and Sarnia, Ontario, Canada.

It moved steadily towards the east-northeast at 35 mph (56 km/h) passing through Tappan before devastating the southern edge of Port Huron some 20 minutes later (Grazulis, 1990) resulting in widespread F3 and F4 damage.

[1] Before crossing the St. Clair River into Canada, the parent thunderstorm dumped heavy amounts of rain and golf-ball-size hail on the city of Sarnia.

[5] As it moved into rural Lambton and Middlesex Counties, more F4 damage was inflicted upon farmsteads and homes near Nairn, before the tornado dissipated south of Stratford around 7 pm EDT (Grazulis, 1990).

In the days to come, radio stations in Detroit, Windsor, and London would aid in the relief effort by relaying messages and emergency information from CHOK to listeners around the region.

Nevertheless, the work of local radio announcers such as Karl Monk at CHOK and Robin Busse at WTTH, who had kept listeners informed of the storm as it developed until their stations were knocked off the air, was credited for saving many lives.