BHOPAL, India (Reuters) - First it was an acidic smell, then a slight itching of the throat, a burning sensation as I sucked in the air. This was Bhopal, and history had come to visit.
I was looking for an innocuous pipe, one of a maze that juts out from Bhopal's plant. The leaking pipe still stands, 24 years after it spewed toxic gas into nearby slums, killing at least 8,000 people in one of the world's worst industrial disasters.
In search of that pipe, I had strolled through this plant just outside the city with a government permit in hand, accompanied by a bored-looking policeman and my guide, Sanjay.
By an old rusty tank near one of the plants, I suddenly smelt something acidic, what survivors had told me hit them as clouds of gas drifted over their homes before they started choking, panicking, and going blind.
"It smells like benzene," said the policeman, as if that piece of wisdom would reassure me.
I was later told the odour could be from a chemical used to make Sevin, the pesticide then manufactured at the plant by U.S.-based Union Carbide Corporation.
If ever there was evidence of bureaucratic inertia, legal squabbling, and corporate wrangling, it was that nearly a quarter of a century after the tragedy the smell of untreated chemicals still lingered.
Around midnight on Dec 3, 1984, some other chemicals used to make Sevin accidentally mixed with water and sparked a chain reaction that led to half a million people being poisoned by gas.
Aside from the cobwebs and rust, the plant is much the same as it was in 1984. More than 300 tonnes of waste, left lying around in drums, were only stored in a warehouse in the complex three years ago.
Sanjay guided me. He had survived the tragedy when he was a baby. His parents and five brothers and sisters died. He grew up in an orphanage, and in a story of a life against the odds, has now applied to take a master's business degree.
"The first time I came here I was so scared," he said as we strolled along a dirt path between plant buildings.
"This was the factory that killed thousands of people, my parents. Now I don't mind, I'm used to it."
I didn't believe him. He spoke often that day of his family, his brothers and sisters, a mum and dad who must have nursed him, played with him for just six months.
Two of his siblings survived the disaster. A sister is married and a brother committed suicide a few years ago.
As we walked, I imagined a 6-month-old baby, probably crying, perhaps left under a blanket by the mother, alone in a slum in one of the world's toughest places to live. And now he spoke fluent English, had girlfriends and ambitions.
We strolled on outside. It was a spring day. I could hear birds singing and kids laughing, somewhere by the compound wall.
Inside, though, the complex is the kind of place you imagine after a biological attack, where everything is suddenly abandoned.
Bottles of chemicals covered in cobwebs still lie in laboratories. Plant safety warning signs still hang from walls. Abandoned tables remain in place. A beehive has found a home in the roof of one plant building.
But if time stood still, pollution may not have.
Environmental campaigners say thousands of tonnes of waste lie underneath, seeping into ground water of nearby slums and causing clusters of diseases, from cancer to birth deformities.
The government says the plant's toxic residues have almost disappeared, washed away after years of monsoon rains.
We entered the control room, treading carefully to avoid broken glass and cow pats where technicians once stood. Outside were patches of ground where grass still failed to grow after 24 years.
We arrived at the tanks where the killer chemical was stored just before the disaster. The tanks lie in undergrowth, looking like a disused locomotive.
As we walked outside the compound, by a slum near a railway track, residents complained about lung diseases, deformities in children, strange rashes. Mothers complained about the stunted growth of children.
Many poor migrants arrived here 24 years ago because the land was so cheap after the disaster.
Here, the government has even painted water pumps red, saying they are not safe. Most locals do refuse to drink it, but still use the pumps for bathing. Young children play in the water.
Next to the slum is the factory's evaporation pond, where toxic waste was once dumped. The liquid was left to evaporate, leaving a sludge. It still overflows in monsoons. Sanjay said he saw kids wash their bottoms in it after defecating.
The trouble is there so far is no smoking gun, no long-term health study that can tell 100 percent why these people are ill.
So everyone here lives in doubt, wondering if something invisible is quietly killing, deforming their children.
"I am scared for my children," said Anees Ahmad Nawab, a carpenter. "I don't know what is lying within that factory."