Seventy-five years ago this spring, the German Luftwaffe carried out a series of bombing raids on the industrial heart of Northern Ireland. A total of 955 people were killed and more than 1,500 injured in what came to be called the Belfast Blitz.

The deadliest of four attacks occurred 15 and 16 April 1941. This weekend, the city is unveiling the first in a series of memorial plaques marking key locations of the attacks, plus other commemoration ceremonies.

“It was very frightening — you could hear the drone of the planes and then the bombs exploding and the ground shaking beneath you,” survivor John Kielty, 87, a retired postmaster who was 12 at the time, told The Belfast Telegraph.

The BBC offers a great package of words, images, videos and interactive maps about the events: How did an elephant beat the Belfast Blitz?

The six counties of Northern Ireland were partitioned from the rest of the island in 1921 and remained part of the United Kingdom, which declared war on Germany in 1939. There were also several German bombing attacks on neutral Ireland in 1940 and 1941.

After the bombs dropped on Belfast in 1941.