"Run away!" the husband screamed from a rooftop after he spotted the colossal waves.
The command was simple, but it presented Sangeeta with a dilemma: She had three sons, and only two arms.
She grabbed the youngest two and ran -- figuring the oldest, seven-year-old Dinakaran, had the best chance of outrunning the tsunami churning toward her home.
But Dinakaran didn't follow. He headed for the safest place he knew, the small family hut just 40m from the seashore.
Sangeeta thought she would never see him again. The family dog saw to it that she did.
While water lapped at Sangeeta's heels as she rushed up the hill, the scruffy yellow dog named Selvakumar ducked into the hut after Dinakaran.
Nipping and nudging, he did everything in his canine power to get the boy up the hill.
Sangeeta, who like many south Indians only uses one name, had no idea of the drama unfolding below. Once she had crossed the main road to safety she collapsed into tears, screaming over the loss of her eldest son.
"I had heard from others that the wall of my house had collapsed, I felt sure that my child had died," said the 24-year-old mother.
Selvakumar looks pretty much like every other dog in the village. He hardly ever barks and lets the three boys climb all over him and pull his tail without protest. At night, he joins the rest of the family and sleeps among them, no matter how many times they throw him out.
Most days, the dog escorts Dinakaran to and from school, spending the rest of the day playing with the other two boys, or begging for food.
Sangeeta's brother-in-law gave her the puppy, following the birth of her second son. When the brother-in-law died in an accident two years ago, they changed the dog's name to his.
Sangeeta's family had always lived along the coast, just north of Pondicherry, a former French colony.
The morning of Dec. 26 began like most others, with sunny skies and a cool breeze.
Sangeeta's husband, R. Rama-krishnan, had just returned from his early morning fishing with a boat full of fish.
From their home, the view of the ocean was obstructed by a two-story community center. So when they heard a strange noise coming from the sea, Sangeeta's husband went to investigate.
When Ramakrishnan saw the waves, he ran to the roof of the center and shouted down to San-geeta to flee. That's when she made her agonizing choice.
"He is somewhat older than the other two. I knew he would be able to run, so I grabbed the other two," Sangeeta explained.
Dinakaran credits the dog with saving his life.
"That dog grabbed me by the collar of my shirt," the boy said from under some trees at Pondicherry University, where the family is waiting for relief. "He dragged me out."
Sangeeta said she wept with joy when she saw her son walking up to her, with Selvakumar by his side.
The Tamils of south India believe that talking about the death of a living person can make it so, so Sangeeta didn't want to mull over her decision or speculate how she would have felt had her son not survived.
She did say that she believes some special spirit, perhaps her brother-in-law's, resides in the young yellow dog.
"That dog is my God," said Sangeeta -- with Dinakaran sitting on the ground at her feet and Selvakumar sleeping on the warm asphalt next to him.