Nobody could confirm if the bus was in motion when she alighted. "Even if the bus was moving, it would have been very slow because of the procession," a witness said.

The bus driver was arrested on the spot and booked for rash and negligent driving. A traffic sergeant rushed Sita to Calcutta Medical College and Hospital, but cops from Girish Park police station ostensibly missed the arm that was lying on the road.

When Sita was wheeled into an operating theatre around 3.30pm, four hours after the accident, her severed right arm still hadn't been retrieved for doctors to attempt a reconstructive surgery.

"This is a case of traumatic amputation. Had the arm been properly preserved and alive, we might have attempted reconstruction," said Priyojit Chatterjee, a senior doctor at the hospital. "But at least we managed to save the patient."

Hospital superintendent Sikha Banerjee said the police informed her "late in the evening" that one of their officers deposited the severed arm at the morgue since he wasn't aware that the doctors might ask for it.

When Metro visited her bedside, Sita opened her eyes once and mumbled: " Bahut dard ho raha hai (I am in great pain)."

The hospital has sought a detailed report from the team of doctors who treated Sita after she was brought in. "I have asked the orthopaedic team to submit a detailed report on when the patient was admitted, when she was taken to the OT and what was the information they had about the severed arm," superintendent Banerjee said.