IRAQ: Inside the Canal hotel the working day was drawing towards its end, but the blue and white UN building was still a hive of activity.
A briefing about landmines was in full swing in the conference room, while in the corridors and meeting rooms there was the typical UN activity - conversations and jokes in different languages between the dozens of races and nationalities who have rushed to Iraq since the war.
None of the 300 UN workers, many of them Iraqi, who were going about the business of bringing humanitarian relief were prepared for the fact that they were about to become its latest victims.
It was just after 4.30 p.m. when everything inside the building went black. A video camera at the briefing recorded the sound of a huge explosion, followed by crashing and breaking glass, and then piercing screams and shouts.
Mahmoud Shaker (42), an Iraqi translator, was in the room. The right shoulder of his shirt was spattered with the blood of those he had helped to carry outside.
"Everything just went black. Somebody was shouting: 'Everybody stay where you are. Wait for the electricity to come back on.' People were screaming and shouting. We headed for the windows. People were very brave and were helping each other to get out."
Not everybody was so lucky.
The bomber or bombers crashed the truck into the perimeter wall as close as they could get to the left-hand corner of the building. If UN envoy Sergio Vieira de Mello was the target they knew what they were doing.
The Canal hotel, which before the war was home to the UN weapons inspectors, was unrecognisable.
The corner of the building at all three levels had fallen into the car-park. The Internet cafe on the ground floor was destroyed. In the glass-fronted cafeteria, renowned among aid workers and journalists for serving some of the best food in Baghdad, tables and glass were blown across the room.
Outside, local people chased a small group of men they claimed had been responsible for the explosion.
As the dust settled some of the UN workers at the compound began to emerge dazed and confused from the wreckage. The question most seemed to be asking was why the UN? Why us? The walking wounded were pushed into trucks and driven away as ambulances began to arrive at the scene.
As more US soldiers in tanks and armoured personnel carriers sealed off the roads around the hotel, Blackhawk helicopters marked with red crosses began to arrive. American soldiers in T-shirts combed through the rubble. At first it was reported that Mr de Mello was alive. Colleagues, it was said, were trying to give him water. He had called emergency services using his mobile, another report said.
More than three hours after the explosion, the Blackhawks, their rotor blades whipping up clouds of dust as they landed three at a time in rotation, were still ferrying the wounded to military field hospitals around Baghdad.
One UN employee had gone across town to another office and returned to find ambulances speeding by and American soldiers scrambling through the destruction. She sat on the street and wept as she told a soldier that her niece was inside.
"Let me in please. Let me in," she said, waving her UN badge.
"Oh God, why is this happening to us? Oh God, let me in."