Two hundred years ago today lightning struck a gunpowder warehouse in Luxembourg City. It set off a huge explosion that destroyed buildings all around and killed 230 people.

Church vaults were often used to store large quantities of gunpowder, a terrible place to hoard explosives as lightning frequently strikes high church steeples.

In 1769 lightning hit the tower of a church in Brescia, near Milan, and blew up the 100 tons of gunpowder stored there. The explosion levelled one sixth of the city and killed about 3,000 people, possibly the world’s worst recorded lightning disaster. The church authorities had turned down the chance of fitting the newly invented lightning conductor on the ground that it was heretical to interfere with divine will.

On May 15, 1777, the Navy’s gunpowder magazines at Purfleet, Essex, were struck by lightning soon after pointed lightning rods had been fitted. Only chunks of masonry and bricks were dislodged, but even this limited damaged was regarded as a failure and sparked a furious debate about whether pointed or round-topped lightning conductors were safest. George III decided that rounded tops should be used and ordered that the lightning rods on his palaces should have a cannon ball placed on top of them. In fact, recent research shows that he was correct – rounded conductors are more efficient at lightning protection than pointed tips.