This sounds bad.
A4200 Southampton Row Bloomsbury, both ways between A40 Bloomsbury Way and B502 Russell Square
A4200 London - A4200 Southampton Row in Bloomsbury closed and queueing traffic in both directions between the A40 Bloomsbury Way junction and the B502 Russell Square junction, because of a serious accident involving lorry and a cyclist
According to ‘Dooks’
Just passed what looked to be a very nasty accident southbound on southampton row. articulated lorry stopped in the road at an angle, a battered green ladies mountain bike by the side of the road a crowd of horrified onlookers and paramedics peering under the wheels of the trailer. ambulances were just arriving on the scene as i passed. Did not look good.
John Lew has posted this photo on Twitter (which I have cropped - the original is here).