The BBC's Tim Franks witnessed the moment a man driving a bulldozer ploughed into a bus and cars in Jerusalem.
An Israeli policeman shot the driver dead inside the bulldozer's cab
At first I heard screams.
Then, as I looked out of the office window at the Jaffa Road below, I saw a bulldozer ram a bus again and again. The bus flipped on its side.
I couldn't quite believe what I was seeing, but then my astonishment grew further when I realised that this was a deliberate attack.
The bus went over, apparently very, very easily... of course with people inside it.
At that point, we careered down onto the street to see in more detail what was going on, and by the time we got down there, the bulldozer had gone maybe 100m-150m (330ft-500ft) further down the road, and had come to a halt, but not before several cars and taxis had been run over with people inside.
It was a grisly scene, and horns were still blaring.
Woman driver 'flattened'
I spoke to a security guard I know, from the bank next door, who told me he had killed the driver.
But he clearly hadn't because then, just a few metres in front of us, the bulldozer started off again down the street, slowly zigzagging with - extraordinary to relate - two people, maybe three, inside the cab, having a huge fight.
The cab was shaking violently as the tussle went on.
The bulldozer itself was only moving slowly and it allowed an Israeli policeman to climb on the bonnet.
He loosed off several shots at point-blank range into the driver's head, which jerked against the side of the cab. His body was dumped onto the street.
He had been only a couple of hundred metres from Jerusalem's main market.
It was at that stage that we were able to back off and have a look at the trail of destruction, which was remarkable and unpleasant to look at.
There was a woman driver who had been flattened by the bulldozer, still somehow wedged behind her steering wheel.
And it was a few minutes after that that the Israeli security forces started screaming at us to get out of the area because they feared that there were explosives on the bulldozer - that may have been just precautionary rather than any intelligence.
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