Help me with this novel

Hi friends,


I read a novel long years before.But don't know exactly the story and details about the novel.
Here i am explaining the story,what i had remembered.

There was four main characters, which was hero and his brother,heroine and her sister.Hero's brother and heroine's sister were in love with each other.At a stage,they ran away from their house.Hero and heroine were trying to chase them.At the chase, they accidentally met in an earthquake.
In that earthquake,they both survived luckily.A chemistry worked out between them.But they fought with each other unknowingly.Finally
they heard that the hero's brother had admitted in a hospital,they all met in that hospital.At last the heroine's sister found that they were loving each other.
The story completes with a happy ending love story.

This what i am remember from that story,If anyone kindly post me the novel name or author name or the pdf link