Preliminary reports from the site of the NTPC blast have revealed that safety norms were violated, and the regular exercise of de-choking the bottom hopper of the boiler turned disastrous at the Unchahar plant in Rae Bareli, The Indian Express said. The death toll from the accident shot up to 29 on Thursday

A report in the paper on Friday explained: According to information gathered from multiple sources, the 500 MW Unit No. 6 was running at a load of around 200 MW on Wednesday. Sources said the bottom hopper de-ashing was being done by opening the manhole door at around 10 metres height on the boiler platform, by an NTPC maintenance team. The boiler was in manual mode of operation. Suddenly, the furnace pressure increased and hot clinkers of ash fell in a splash, injuring those in the vicinity. This was reportedly followed by a blast due to the increase in pressure, resulting in the release of flue gas at very high temperature from a duct at 20 metres height in the boiler.

De-choking the bottom hopper using rods to push out ash clinkers while the boiler is in operation is against safety norms.

The report also said that the NTPC did not corroborate or deny the sequence of events when questioned about the same.

Congress vice-president Rahul Gandhi, who visited the blast site, tweeted: “Labourers have said that the accident took place due to negligence and that there should be a judicial probe into the accident and strict action should be taken against the guilty.”

A magisterial probe has been ordered into the incident and the National Human Rights Commission has issued notice to the UP government, asking the chief secretary to submit a report in six weeks.