Trapped under the debris of his derailed coach, Sanjeet Kumar escaped death only because of a steady flow of WhatsApp messages from home.

Sanjeet, mechanical engineering faculty at Corporate Institute of Science and Technology, Bhopal, was one of the passengers on the Indore-Rajendranagar Express. He was completely trapped under the train roof but for his face and chest when the train derailed at Pukhrayan, 75km south of Kanpur.

He remained like that for almost six-and-a-half hours in his 3AC B3 compartment before relief came.

Sanjeet's family in Digha heard about the incident after he managed to catch hold of a fellow passenger - relatively unscathed from the next coach - to call his relatives. That was around 3.15am. Sanjeet's brother-in-law Sanjay Kumar kept on messaging and calling him till the Bhopal institute assistant professor finally responded with pictures at 7.12am.

The pictures went a long way in rescuing him.

"One of our relatives live near the derailment site and we showed Sanjeet's message and his pictures to the people working in the rescue team through him," said Sanjay. "It helped them locate his position and rescue him. The rescue team was shown the message at 9am and Sanjeet was rescued by 9.30am."

The pictures were also shared on the railway ministry's Twitter handle. The family claimed the ministry took notice of it and kept communication lines open.

But while the family was worrying, Sanjeet was slowly losing hope.

"Sanjeet first informed us about the incident at 3.15am, minutes after the incident, through another passenger. For the next four hours we kept calling him but Sanjeet did not respond," said Sanjay. "When we finally got in touch with him, he had almost lost hopes of surviving. He said his chances of survival were only 50-50 and asked us to locate him fast."

"We could not let him lose his willpower at that time. So we kept on talking to him, asked him to stay strong. Thankfully our messages affected him in a good way."

After Sanjeet was extracted from the wreckage, he was rushed to the district hospital in Kanpur. His mother Sarita Devi did not, however, rest easy till she heard Sanjeet's voice for herself at 11am.

"Sanjeet was first rushed to the district hospital after being rescued," she said. "I had requested the doctor attending to him to let me speak to him. I was being told about Sanjeet's WhatsApp messages but I could be normal only after speaking to him."

Satyanarayan Singh, Sanjeet's father, an engineer posted in Muzaffarpur, left for Patna soon after he heard of the mishap at 4.45am.

"Sanjeet was coming to Patna to attend a wedding in the family. He had come home on Diwali but I did not meet him then because I did not have leave. It has been more than five months that I have not seen my son," said an emotional Satyanarayan. "Now that this tragedy has occurred, I want to meet him as soon as I can. Still, it might take a while longer, as I have to join work on Monday. I will apply for leave soon. Let's see what happens. I have sent my elder son Sandeep to the private hospital (Regency Healthcare) where Sanjeet was shifted to from the district hospital."