Mahi Upadhyay died within 3 hours after falling into the 68-feet-deep borewell due to asphyxiation, said doctors who conducted the post-mortem of the 4-year-old on Sunday.
"Since Mahi fell into a borewell, which was extremely narrow (1.5 feet) and exceedingly deep, there was clear exclusion of air and correspondingly of the oxygen level required to sustain life. Mahi probably had difficulty in breathing and it was because of suffocation that she died within two to three hours of her fall. Even an adult could not have survived in such difficult conditions," said Dr Dipak Mathur, the member of a panel of doctors who conducted the post-mortem.
The minor victim's body was recovered in a highly decomposed state suggesting that she had passed away days ago.Further, according to rescue workers, the borewell had started smelling foul from Thursday.
"Lack of oxygen caused the suffocation. There was no external injury or bone fracture," the doctor added.
Mahi was heard screaming and shouting for help for about 95 minutes after she had fallen into the borewell at 11.10pm on Wednesday, but fell silent after 12.45am on Thursday.
The administration was slow in responding to the distress call as an oxygen pipe - which was only 8-feet-long - was lowered down three hours after the incident. That means the child spent hours without sufficient oxygen supply.
Without sufficient oxygen to sustain life, people will act normally at first but will soon collapse in a few seconds as the remaining oxygen in the blood is consumed, say experts.
The experience of the five-member rescue team of army jawans of the 3rd Army Engineers Regiment corroborated the fact that the depth of the pit made breathing difficult.
Most of them could not breathe properly for more than 7-10 minutes at a stretch and had to take turns to carry out the rescue work.
Only one of the jawans was able to manage at a stretch for 15 minutes. Further, oxygen deficiency forced the jawans to use gas masks despite oxygen being supplied in the borewell through pipes.
Though the temperature at the bottom of the pit was found to be five degrees lower than the surface temperature, the humidity was very high inside.