The double-decker bus with 53 passengers on board was on its way to Delhi from Lucknow when it hit a divider and fell into the 40-feet-deep gap between two flyovers on the Yamuna Expressway near milestone 161 (Jharna nallah) under Etmadpur police jurisdiction of Agra district at around 4.15 a.m.
At least 29 people were killed in the accident. Police reports said that 20 passengers had been rescued and efforts were on to rescue the rest.
Villagers from Chaugan, near the 'deadly' Yamuna Expressway entry point, said they rushed to the accident site after hearing shrill wails and cries for help.
Nihal Singh jumped into the nallah, broke open the window panes of the bus and extricated several bodies in the dark, while some rushed to inform the police and the gram pradhan, who immediately rushed two JCB machines. Two boys, practising for army recruitment, also joined the rescue work.
While the injured were rushed to nearby Krishna Hospital and the seriously injured ones to SN Medical College, the bodies were sent for post-mortem.
"Those of us who saw the injured or the dead, couldn't believe life could be so uncertain. Most were asleep, unaware of what had transpired, as it was still dark," said an eyewitness.
Prime Minister Narendra Modi expressed grief over the tragedy. Uttar Pradesh Chief Minister Yogi Adityanath too condoled the deaths and announced an ex-gratia of Rs 5 lakh each for the victims' kin.
He also instructed officials to expedite rescue and relief work at the spot, adding that proper treatment should be provided to the injured. A special helpline number 1800102877 was also announced to give information about the victims. A list of the injured and the deceased has also been circulated by the police.
Onlookers blamed the accident on the Yamuna Expressway, which has taken a heavy toll of lives since its opening in 2012. "Earlier we had only Yamuna Expressway but now the Agra Lucknow Expressway is competing in the killing spree," said social activist Shravan Kumar Singh.
( With inputs from IANS )