The crushed train cars were cleared and the jumbled tracks straightened and rejoined, as workers labored on Sunday to quickly restore an important rail line in east India two days after the country’s worst train disaster in decades.
Families of the victims were still struggling to reach the site of the wreck, near the town of Balasore in Odisha State. Officials intensified the investigation into the cause of the crash, saying that while they were looking into the malfunction of an electronic signaling system, they did not rule out human error — or even sabotage.
The desperate journey to claim the bodies of loved ones was complicated for many families by a lack of train service, though by late Sunday night, some rail movement on restored tracks began in both directions. Officials said a special train would ferry relatives from the city of Kolkata, in the neighboring state of West Bengal, to Odisha. And the government of Odisha announced free bus service on the disrupted train route.
“Most of these people are poor, and it may take them days to arrive,” said Rahul Kumar, a doctor at the main hospital in Bhubaneswar, the capital of Odisha, who was helping with the rescue and relief efforts.
Information about the cause of the three-way accident has been piecemeal. What is known so far: A high-speed passenger train collided with a parked freight train around 7 p.m. Friday and derailed. Some of its cars slammed into another passenger train, leaving a sprawling tableau of twisted metal, crushed limbs and splattered blood.
India’s railway network is one of the largest in the world, transporting eight billion passengers a year. The disaster cast a pall over Prime Minister Narendra Modi’s efforts to modernize the country’s infrastructure, which he has made central to his campaign for a third term. Mr. Modi’s government has frequently publicized its investments in expanding infrastructure, but a recent official audit noted a glaring imbalance in the budgets.
While India was drastically increasing overall spending, including for a fleet of new semi-high-speed trains, the amount it has invested in safety for the rest of the fleet of more than 13,000 trains was decreasing, the audit said.
India’s railway minister, Ashwini Vaishnaw, told reporters on Sunday that officials were investigating whether the electronic signal system to prevent accidents had not functioned as intended. But officials left open the possibility of sabotage and vowed punishment for anyone found responsible. The railway authorities have also asked India’s premier investigation agency, the Central Bureau of Investigation, to take over the inquiry, the minister said.
Railway officials grumbled in private that by initiating a high-profile inquiry, political leaders were looking for scapegoats to distract from what has been a well-documented truth: Despite India’s trumpeting that it has reduced the frequency of mass-casualty rail accidents in recent years, the work of assuring safety on the country’s vast railway network remains deeply underfunded.
For the families that traveled to the crash site, the process of identifying and claiming their loved ones was slow and traumatic. Of the 275 people killed in the crash (officials initially said 288 had died but later revised the toll), only 88 bodies had been returned to their families since the crash, officials said. More than 1,100 others were injured.
The government in Odisha on Sunday moved about 100 bodies to the morgue at the main hospital in Bhubaneswar, and it was at capacity. The state government also published online the photos of more than 160 of the dead, many in gruesome condition, to help families identify victims.
About a dozen bodies were also laid out in the hallway of a small school a few hundred yards from the crash site. Others were kept in a business park in Balasore on top of large ice blocks covered with plastic sheets. But the ice was melting fast in the heat. Families who made it to the park first had to look at the faces of victims on a laptop. Then, if they saw any resemblance to a loved one, they moved in for a closer look.
Among the passengers on the Coromandel Express, one of the trains, were two friends, Debpriya Pramanik and Budhadeb Das, who were returning from their village of Baliara, in West Bengal, to their construction jobs in the southern city of Vijayawada. They had persuaded a third friend, Shamik Dutta, to join them.
Mr. Dutta had hardly left Baliara before, but his two friends said they had convinced him that the money they could make in Vijayawada was worth it.
How much? Mr. Dutta wanted to know.
“Enough for people like us,” Mr. Das said he had told him. Mr. Pramanik added that with the money, Mr. Dutta could help take care of his parents.
On the Coromandel Express, the three friends stood near the door of a crowded compartment, where people were packed shoulder to shoulder. Just before 7 p.m. on Friday, Mr. Dutta said he needed to use the restroom and left his bags with his friends.
It was the last time they saw him alive.
Interviews with three railway officials, and press briefings by other officials, offered insight into the moments before the crash.
The Coromandel Express, had departed Kolkata with about 1,250 passengers and was passing the Bahanaga Bazar station in Balasore, traveling at a speed of about 80 miles an hour; it was not supposed to stop there. At the same time, the Yesvantpur-Howrah Superfast Express, with 1,039 passengers onboard, was exiting the station and heading in the opposite direction.
At 6:55 p.m., the Coromandel suddenly veered onto a looping track where a freight train carrying heavy iron ore was parked. As the first train smashed into the freight train, nearly 20 of the passenger cars derailed — some were flung into a farm on the other side and others struck the tail of the second passenger train.
Two senior railway officials, speaking to reporters in Delhi, said they had firmly established several factors: The Coromandel had received a green signal as it reached the Bahanaga Bazar station, the train was not speeding and it had not crossed a red signal.
The tracks are managed by an “interlocking system,” they said, that determines what signal — green to pass, yellow to slow down, red to stop — would be given to a train. While interlocking systems can be managed manually or electrically, the officials had determined that the one at the station was electronic.
“It is called a fail-safe system, meaning it will fail on the safer side,” said Sandeep Mathur, one of two railway officers in charge of railway signaling, told reporters.
Investigators were studying why the loop remained open and whether an additional layer of human oversight had failed. The conduct of officers at the signal house, a stone’s throw from the crash site, as well as managers at the Bahananga station about 500 yards away, was also under investigation, the officials said.
The crash occurred on the South Eastern Railway, a crucial network for millions of migrant workers who travel cheaply on fast trains that cut across India’s heartland. Many of the passengers — like Mr. Das, Mr. Pramanik and Mr. Dutta — were from the poorer eastern and central parts of India and were employed in the more affluent cities in the south.
During the crash, Mr. Das was knocked out and suffered minor injuries. Mr. Pramanik emerged with a fractured arm and head injuries. Mr. Das said he kept looking for Mr. Dutta, but he was not at the hospital where Mr. Pramanik was being treated, so he traveled to a mortuary a few miles away.
It was there where he found Mr. Dutta’s body, wrapped in a white sheet.
Mr. Das said he did not recognize his friend’s face, only the clothes he had been wearing when they boarded the train.
“I don’t know what to tell his parents,” Mr. Das said.
Atul Loke, Karan Deep Singh and Alex Travelli contributed reporting.