(CNN) Family members are mourning their lost loved ones as India reels from a deadly train crash.

More than 140 people were killed when several train cars derailed in northern Uttar Pradesh early Sunday morning.

"All of a sudden there was a massive jerk," Ravindra Pathak said in the aftermath of the deadly derailment. "Our heads collided with the roof of the carriage."

Among the passengers were Rakesh Verma and his new wife, as well as other members of their wedding party.

"There's a little girl, she's two-and-a-half years old, we can't find her or my mother in the wreck," Verma's brother told CNN affiliate News 18.

The train, which links the central Indian city of Indore to the city of Patna in its north east, was halfway through its journey when it went off the track near Kanpur, around 300 miles southeast of New Delhi.

After almost an entire day of work, the site of the accident has now been cleared, Ahmed said.

In total, 110 bodies have been identified, with 97 handed over to the victims' families. Around 50 people remain under treatment in hospital, of 169 injured.

Terrifying accident

One survivor told News 18 the train started shaking with "screeching sounds" early Sunday.

"I felt as though metal was clashing with metal, it was like a collision. My upper berth was almost tilted by the time the train halted," Shresth said.

Shresth -- who goes by one name as do many people in India -- said he was one of the first to climb out of the wreckage. He was traveling with a friend to the city of Lucknow to attend an event, he said.

Indian rescue workers search for survivors in a train wreck near Pukhrayan in Kanpur district on November 20, 2016.

When they tried to leave through one of the doors, they found the corridor littered with bodies, he said.

"I did not want to step on the bodies so we took the other door, but by the time we deboarded, all I could see were either dead people or children crying for their parents," Shresth said.

The pair used GPS navigation to make their way to a nearby village hospital. Later they saw ambulances arrive.

Shresth said the accident "shook him for life."

Onlookers and survivors gather next to wreckage of the train that derailed Sunday near Kanpur, India.

The crash scene

Video from the scene showed mangled carriages flipped over on its side. Fourteen cars in the 23-car train derailed, Modak said. Authorities used cranes and metal cutters to clear the debris.

India's disaster response force spent all day Sunday in what it called a war footing. The army joined rescue operations according to the Press Trust of India.

It was not immediately clear what caused the crash or how many people were traveling on the train, Javeed Ahmed, director general of police for Uttar Pradesh, told News 18.

The government announced aid packages for the families of the bereaved.

Indian Prime Minister Narendra Modi expressed his condolences on Twitter, saying, "My thoughts are with the bereaved families."

Anguished beyond words on the loss of lives due to the derailing of the Patna-Indore express. My thoughts are with the bereaved families. — Narendra Modi (@narendramodi) November 20, 2016

India's railway one of world's largest

Railways Minister Suresh Prabhu told reporters after visiting the site that a high level team will investigate the incident.

"Right now the immediate priority is rescue people and to bring relief to those injured and that's what we are doing," he said.

Visited accident site and reviewed rescue and relief operations.Rescuing people,providing relief to those injured our immediate priority pic.twitter.com/0d2Drqlc2X — Suresh Prabhu (@sureshpprabhu) November 20, 2016

India's railway system is one of the largest in the world, employing 1.3 million people.

More than 23 million passengers ride them every day on journeys that extend from one end of the country to another. Some passengers spend days on the trains.

Despite being the most popular form of long-distance travel in India , several train accidents are reported each year. This is the deadliest disaster in six years.

India's sprawling rail system is state-run, and the government is being heavily criticized on the nation's television networks. The rail system is known to be poorly maintained, and upgrades have been long overdue. In its last budget, the government put aside large sums of money to modernize the system, to improve traffic lights and lay more rail tracks.