Churches and castles were often extremely dangerous buildings during thunderstorms in the days before the lightning rod was invented. Being so tall, they were highly vulnerable to lightning strikes: hundreds of bell-ringers across Europe were killed over the centuries in the mistaken belief that ringing the bells would ward off lightning. But an even greater hazard was the habit of storing gunpowder in castles and church vaults.

Athlone, in the heart of Ireland, suffered a tremendous thunderstorm on 27 October, 1697. "Heaven and Earth seemed to be United by the Flame of this Lightning", described a report; one huge bolt of lightning ripped into Athlone castle, blasting into the arsenal and blowing up 260 barrels of gunpowder. The castle and much of the surrounding town was demolished and all the buildings had to be rebuilt. Incredibly, though, only eight people were recorded killed and about 36 injured, or as one sobering account added: "None Killed of Note".

In 1769, a lightning bolt struck the tower of St Nazaire in Brescia, northern Italy. The vaults stored 100 tons of gunpowder and the lightning strike detonated an explosion that destroyed a sixth of the city and killed 3,000 people. Even after the invention of the lightning rod in 1849, lightning strikes still caused huge damage and calamities. In 1856, lightning struck the church steeple of St Jean in Rhodes, blowing up gunpowder in the vaults and killing 4,000 people.