The passenger train was midway through a 27-hour journey between the cities of Indore and Patna when it slid off the tracks at 3.10am local time on Sunday.
The impact was so strong that one of the coaches landed on top of another, crushing the one below. Passengers said they heard the crash as they were flung from their beds.
“There was a loud sound like an earthquake. I fell from my berth and a lot of luggage fell over me,” Ramchandra Tewari, who suffered a head injury, said from his hospital bed in the city of Kanpur. “I thought I was dead, and then I passed out.”
Rescue workers, soldiers and members of India’s disaster management force worked through the night to pull out people trapped amid the twisted metal and overturned coaches near Pukhrayan, a village outside the industrial city of Kanpur roughly 250 miles south-east of New Delhi.
Rescuers used cutting equipment to pry open cars and cranes to lift coaches from the tracks, moving carefully to prevent any cars from toppling over and injuring those trapped inside.
By Monday morning, they had searched the last of the 14 wrecked cars, finding several more bodies that took the death toll to at least 133, according to local police Inspector General Zaki Ahmad.
Roughly 226 others were hurt, including 76 with serious injuries. Medical teams provided first aid near the site, while those in more serious condition were moved to hospitals in Kanpur.
Anxious relatives searched for their family members among the injured and the dead at hospitals in Kanpur.
Accidents are relatively common on India’s sprawling rail network, which is the world’s third largest, but lacks modern signalling and communication systems. Most accidents are blamed on poor maintenance, outdated equipment and human error.
The derailing is one of India’s deadliest train accidents in at least five years.
According to an Indian government report in 2012, about 15,000 people are killed every year in train accidents. The worst incident occurred in 1981, when a passenger train fell into the Baghmati River in northern India, killing nearly 800 people.
Prime minister Narendra Modi – who said in a Twitter post that he was “anguished beyond words” by Sunday’s accident – had pledged last year to invest £110 billion over the next five years to modernise India’s railway network, which is used by about 23 million passengers per day.