Jimmy Doherty has written a book about the Belfast blitz

He uses a tiny cardboard box and rectangular piece of styrofoam to illustrate why so many people died in the pitifully few purpose-built air-raid shelters.

The styrofoam represents the solid concrete roof, the box the shelter itself.

If the German bomb did not suck out, or blow in, the walls, then the roof collapsed on those inside.

Jimmy went to his own family house to find it destroyed, expecting to find his family dead.

He could not find them that night, but they survived. Still, many of his neighbours and friends were killed.

He identified two bodies of children he knew - one by her curly golden hair and a little boy by the short, white sock on his leg - all that remained of either of them.

The bomb lit in Clarendon Avenue and I must have been hit with shrapnel. It was very frightening

May Gregg

He also described the scene as looking like "a volcano erupting".

Jimmy did not just "do his duty", as he put it, that night in Belfast.

Later he volunteered to go to London as the V1 and V2 rockets fell on the capital in 1944.

Obvious target

After the war, he joined St John's Ambulance Brigade, and found himself, three decades later, once again pulling bodies from the rubble as the Northern Ireland Troubles began in the early 70s.

Belfast was an obvious target for the Luftwaffe - the Harland and Wolff shipyard, and the Shorts aircraft factory were more than enough to make the city, in military terms, a strategic target for the Germans.

Yet Belfast was the least defended city in the United Kingdom. When the bombs finally began to fall in major numbers on Easter Tuesday April 1941, the city suffered the same shock as Coventry.

Jimmy Doherty aged 21 when he was a air raid warden

At least 900 people were killed that night - a total higher than in Coventry, even if the firestorm there was greater.

Luftwaffe bomber pilot Gerhard Becker remembered: "We did not have a mission to attack the city of Belfast... the port... these targets were clearly visible, if bombs fell on the city, we didn't know it, and it wasn't intentional."

Around the targets in the docks area of the Belfast of the day were crowded terraced houses. Back-to-back streets of industrial squalor, the housing of those who worked in the factories and mills.

Rosary beads

Any stray bomb would kill civilians in large numbers.

The dead were stacked in the emptied pool of the Falls Road public baths, and in a market near the city centre.

Many bodies and parts of bodies could not be identified - if there were rosary beads in a pocket, then the victim was likely to be a Catholic.

These targets were clearly visible, if bombs fell on the city, we didn't know it

Gerhard Becker

There are two monuments now at the mass graves where the unidentified dead were buried - one in the Catholic Milltown Cemetry on the Falls Road, the other in the non-denominational City Cemetry, also on the Falls Road.

No-one knows if the identifications were correct. Protestant and Catholic were united in death.

May Gregg was 11 during the blitz. She described what she remembered.

"The bombs were all dropping, and with the noise I put a cushion over my head.

"The bomb lit (landed) in Clarendon Avenue and I must have been hit with shrapnel.

"It was very frightening.

"Still everyone just got on with it in those days, there were some terrible things happening, but that was just part of the war years."

They bred them tough in those days.

Forgotten episode

The blitz on Belfast is, in some ways, a forgotten episode of the war.

The lettering on the two monuments is faded and moss-filled.

Yet it united Protestant and Catholic in suffering - and fire brigades from the Irish Republic twice came north to help out, even though Eamon de Valera's Ireland was neutral.

In his book on the Belfast blitz, (Blackstaff Press, 1989), Brian Barton quotes Emma Duffin, a nurse who was helping out at a hospital near Queen's University in the southern suburbs.

After an incendiary raid by the Luftwaffe just a few weeks after the main attack, she recorded in her diary: "The grass was strewn with blackened and charred papers. There was a sheet from a child's essay book.

"On the top of the page I read, 'The End of the World'. It seemed appropriate. It was the end of the world as we knew it."