The February 13, 1991 bombing of the Al-Amriyah bunker in western Baghdad during the first Gulf War killed 403 men, women and children. It hit world headlines and was trumpeted by Saddam Hussein as a symbol of US "barbarity".

Until the dictator was toppled in the 2003 US-led invasion, each year on the anniversary of the tragedy Iraqi officials would make public appearances at the shelter, which had been transformed into a memorial and a propaganda tool.

But looters descended on the site after the invasion and the military closed public access to the memorial.

Yousef Abbas, who lost his mother, wife and four children when a pair of US smart bombs busted through the shelter's reinforced concrete roof, said he hasn't been back inside "since the beginning of the American occupation."

"When I pass in front I turn away because this place embodies the tragedy of Iraq," said the 60-year-old, bursting into tears as he remembered the night that shattered his life two decades ago.

Occasionally, relatives of the victims show up to recite verses from the Koran, standing outside the perimeter wall that surrounds the bunker which now lies inside a military complex, said Abu Bilal, the keeper of the premises.

The luxurious Al-Amriyah neighbourhood, where the elite of Baghdad had lived under Saddam, is a shadow of its former self, swarming with soldiers patrolling now dangerous streets where Al-Qaeda fighters battle.

Inside the grim bunker, time appears to have stopped in 2003.

'The crimes of America'

From the outside, long ramps descend into a crypt-like darkness toward a maze of corridors, where the street noise fades to silence. The smell of fuel suggests generators once lit the underground complex.

A series of thick blast doors suddenly open into a huge chamber, where a flood of light bursts through a gaping hole in the ceiling where the missiles exploded in nose-dive that blasted the civilians hiding beneath.

The first smart bomb tore through the 2.5-metre (8-foot) thick roof, and a second followed with deadly force, transforming the shelter below into a fatal furnace.

A deep cavity in the floor, charred walls and thick pieces of mangled metal mark the force of that historic blast.

In the eight years of violence that have racked the neighbourhood, the protective glass canopy that once plugged the hole of the roof has also shattered.

The floors are littered with black-and-white portraits of the victims that once were on walls, but now are covered with cobwebs and dust.

In the dark, rare visitor’s trip over slabs of plexiglass on the floor, placed to preserve and display bloodstains and chunks of human flesh to the public when the memorial was open.

After the attack, the Gulf War had pushed Iraqi troops out of neighbouring Kuwait, and Washington maintained that the bunker was hiding as military command post.

"But didn't the Americans have satellites to know that it was a civilian shelter?" Hussein Nasser, who lost his mother and five siblings in the bunker, asked incredulously.

"They knew very well who was inside, but they wanted to strike hard to overwhelm the Iraqi regime," said the 46-year-old, adding that he was raising his three children to hate "the crimes of America".

Outside the bunker, under a wall painted with the colours of the old Iraqi flag, hundreds of tombstones erected over mock graves are now covered with overgrown weeds.