By John Sudworth
BBC News, Mumbai
Mr Cameron toured a project in one of Mumbai's poorest areas
David Cameron has come to India to champion the country's economic success. But India's runaway boomtime is only one side of the story.
Mr Cameron and his entourage have discovered the other side in the worst way possible.
Mumbai is a bustling, vibrant city that is growing ever richer on the back of India's economic miracle.
Yet on many counts it remains stubbornly a third world city with its crumbling infrastructure and slum housing.
And of course its dreadful road system - congested, chaotic and dangerous.
Members of Mr Cameron's staff travelling to meet the conservative leader for lunch were involved in a road accident that has left a female pedestrian seriously injured.
Journalists who were also travelling in the minibus, provided by the British High Commission, say they repeatedly asked the driver to slow down.
David Cameron began his speech to Indian business leaders by saying how deeply saddened he was by the incident.
It was a difficult beginning to a trip that was meant to be a celebration of India's emergence onto the world stage.
Despite the traditional Indian welcome shown to him - elephants, dancing girls and the pouring monsoon rain - the Tory leader is here to see the modern face of India.
He found it on the campus of an IT company, TCS, one of more than 500 Indian businesses with a base in London.
Mr Cameron believes this should be a wake-up call for the UK.
"Now we must wake up to a new reality," he says.
"As the world's centre of gravity moves from Europe and the Atlantic to the south and the east I believe it's time for Britain and India to forge a new special relationship."
The more than one million people of Indian origin living in the UK makes the country ideally placed to take advantage of the huge economic opportunities presented by India's breakneck growth, Mr Cameron believes.
He is also using this trip to highlight that other India - the one where nearly a third of a billion people still live in desperate poverty.
While poverty can only be tackled through economic growth, he argues, there needs to be a moral dimension to the free-trade policy.
Dripping wet with rain Mr Cameron made an unusual figure navigating the narrow alleyways of one of Mumbai's poorest areas.
He was visiting a project providing computer literacy classes for slum children, some of those who've been bypassed by globalisation.
"We can't argue that globalisation is a massive transforming force, but then pretend that the transformation is always and in every way benign," he says.
"We must recognise our moral obligation to the people and places left behind."
While praising the Indian government's moves to open up the economy, Mr Cameron says more could be done, particularly in banking, insurance and legal services, areas of strength for the British economy.
And he has also said that if the Doha trade talks can't be restarted consideration should be given to a bilateral India-EU free-trade agreement.
The Conservative leader says India will become vitally important to the UK's future prosperity.
Critics may say this latest foreign adventure is part of a quest for statesmanship. Mr Cameron says it is about UK interests and the huge opportunities offered by the new Indian economy.