In the remote north-west Indian village of Gandaman in Bihar state, the sight of men with newly bald heads is striking and poignant.
Normally it is Hindu children who shave their heads when a parent passes away, but here fathers are marking the loss of their children – many children.
It is here, in June, that 55 school students between five and 10 years old, sat down to a government-sponsored lunch.
In the hours that followed 23 would die from what they ate – a soy-bean curry, tainted with pesticide.
The chemical monocrotophosis banned in Australia and many other countries, including the United States and China, and regarded by many as one of the most deadly pesticides.
However, its is popular among India farmers because its patent has lapsed and it is cheap.
It is marketed as an effective broad spectrum organophosphate insecticide, but the World Health Organisation (WHO) labels it "highly hazardous" on the basis a teaspoon of it can kill, it is easily absorbed through inhalation and skin contact, it is highly detrimental to the environment and it is extremely toxic to bees and birds.
Local police investigating the deaths of the children sent samples of the food to a government laboratory in the state capital, Patna, and within 48 hours they had conclusive results.
Monocrotophos was identified at 52 times the level considered to be safe.
Superintendent Kumar says: "It was around 52 times higher than the permissible level and that's why the results were so fatal, very high mortality was found because the amount of poison in the food was very high."
Yet Rajju Shroff, the head of United Phosphorus, India's largest producer of monocrotophos, is defiant.
He tells Foreign Correspondent he will close down his factory if it is proved beyond doubt that monocrotophos was the lethal ingredient in the lunch that killed the children.
Mr Shroff dismisses the police findings as "totally bogus".
"There's no report. I mean, I can tell you something, Indian, the forensic laboratories, particularly the police department are famous for manipulating and collecting money and bribes," he said.
Ravi Agarwal, an anti-pesticide campaigner and the director of Indian NGO Toxics Link, has come up against Mr Shroff in the past.
"He's powerful. I do know that he is particularly vocal and takes legal action against anyone who speaks out against pesticides," he said.
In the wake of the deaths of the school children, Mr Argawal and others are calling once again for monocrotophos to be banned in India.
"Why are these pesticide containers available on the shelf? Why is the use of pesticide so poorly regulated in the country?" Mr Argawal said.
"When you deliver nuclear weapons you don't make them widely available, you treat them carefully."
The WHO has urged India to follow the example of other countries and ban monocrotophos, but the Indian government on the advice of industry leaders, like Mr Shroff, has resisted imposing a ban.
Indian agricultural minister Sharad Pawar reportedly says he is looking at the recommendations of an expert committee before he considers placing further restrictions on the use of monocrotophos.
"Use of monocrotophos has accordingly been banned on vegetables," he has been quoted as saying.
"However, its use on crops like cotton, paddy, maize, pulses, sugarcane, coconut, coffee, etc is still allowed, keeping in view its bio-efficacy and cost effectiveness."
If the makeup of the expert committee is anything like the makeup of such committees in the past, the chances of the government banning monocrotophos are slim.
In the village of Gandaman, the families who lost their little ones are not convinced they will get the answers they need and the justice they demand.
A village elder, riding his pushbike, pulls up on the side of the road to tell Foreign Correspondent: "House after house has been destroyed. Can a man of such a family be in peace? He cannot be at peace.
"It takes a long time to bring up a child. What would they have grown up to become?"
One couple lost three of their four children and are now trying to rebuild their lives with their surviving 18-month-old daughter. A 14-year-old boy tells of burying his little brother with his own hands.
They are poor, powerless lower caste families too easily ignored by powerful politicians.
Bihar state's chief minister Nitish Kumar has declared the incident the work of political saboteurs out to discredit the India-wide midday lunch program that feeds 120 million Indian children every school day.
He believes his political enemies conspired to poison the children and that the school principal, Mena Devi, was somehow complicit in the plan.
Ms Devi is in custody facing criminal and civil charges but her role in the incident is far from clear.
She is variously accused of negligence or of a enacting a premeditated plan to harm the children.
Dr Nigam, one of the paediatricians who treated the children when they arrived at Patna Medical Centre, is in little doubt of the need to enforce greater restrictions on the pesticide to ensure that such a tragedy does not happen again.
"I think in the history of my medical service, I think this was the most hair-raising experience for me," he said.
"In fact, never ever I remember that I would, would've met so many children and in such a situation that they are going to die immediately."