Most of the casualties were students
One second Yury Lichkaty was travelling in his seat on a commuter train on a bright winter's morning in the Russian North Caucasus - the next, he was struggling for his life amid twisted metal and shattered bodies.
The huge blast ripped the floor of his carriage apart and punched a hole through the roof, killing or mortally wounding some 40 people, injuring scores more.
"The woman who was in front of me died on the spot," Mr Lichkaty, his head swathed in bandages, told the French news agency AFP from his hospital bed.
"I managed to crawl out though a door which was half-open but I was hit by the luggage-racks and glass fragments cut my head."
Rescuers arriving on the scene found the embankment strewn with bodies interspersed with passengers' belongings, including satchels.
Some 90% of the victims were said to be local students in their late teens or early twenties.
One 75-year-old local resident who rushed out after the blast witnessed the horror:
"I rushed outside, there were cries, groans, blood everywhere.
"I saw limbs lying around, they started to collect them quickly in
An elderly woman resident who spoke to Russian TV described the shock wave from the blast:
"It was so strong that it smashed all the windows.
"The cup of tea I was drinking was sent flying. I felt as though I had been picked up and put back down again."
In September, a bomb struck the same railway service out of Yessentuki and local people were angry at what they saw as the inaction of the security forces, AFP reports.
"This is the eighth terror act in the past three years here, people are dying by the dozens and they are doing nothing," said one woman.
"They can't protect us."