Loughborough MP Nicky Morgan says she "heard an almighty bang" and "saw clouds of thick black smoke" as the helicopter crashed into a crane in South London this morning.
The MP was walking towards Vauxhall tube station, when the accident happened.
"Ms Morgan says she "saw clouds and clouds of thick black smoke billowing from the ground" and that initial thoughts were that a bomb had exploded."
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Despite receiving treatment at the scene, the man was pronounced dead shortly after.
Cloud will largely clear this evening, although with variable cover and few light showers over the Derbyshire hills.
The rain will clear during the evening so the rest of the night will be dry and mild with long clear periods.