On the 11 April 2011, Arunima  Sinha was on a train to Delhi. A national-level volleyball and football player, Arunima was on her way from Lucknow to write an examination to join the Central Industrial Security Force.

She boarded the unreserved compartment of the Padmavati Express on April 11. During her journey,  thieves attempted to snatch her bag.

When she resisted, they threw her out of the running train, and before Arunima could make sense of anything another train came rushing by and ran over her leg.

She lost her leg in this horrific accident. And her world turned upside down. People around her suddenly started "looking at her with pity". And so, she decided, she "would do something to prove herself".

A few days later, she was admitted to AIIMS where experts fitted her with a prosthetic leg. And that's when she decided her life's mission.

Later in 2011, Arunima got in touch with Bachendri Pal, who was the first Indian woman to summit Mount Everest, and began training under her.

Over the next two years, Arunima climbed several peaks as she prepared to achieve the goal she had set for herself while lying in a hospital bed with her leg cut off.

And at 10:55 am on May 21, 2013, Arunima Sinha achieved that goal. She was on top of the world, literally.

Her excitement knew no bounds. "I felt like throwing my arms in the air and screaming," she said about her moment on Mount Everest. "I wanted to tell everyone that I'm on top of the world, especially to those people who thought a woman and an amputee couldn't do it. I took off my mask and screamed, and my Sherpa just stared at me."