The father of a 10-year-old boy rescued from strong waves off the California coast in a dramatic scene captured on video says he is beyond grateful to the teenage lifeguard who saved his son.

“He ran into that water despite those conditions that are deadly. There are 10-foot waves; there are currents coming in,” Sumit Rai told The Associated Press on Wednesday. “It’s not safe for him to go into that water. So he’s risking his own safety.”

Rai’s son, Nathaniel, was standing in shallow water when he lost his balance and was swept into the ocean Saturday by powerful waves that suddenly came ashore at Seabright Beach in Santa Cruz, about 60 miles (about 100 kilometers) off the coast of San Francisco. Rai, who was in his hometown of Dallas, said he found out what happened when he spoke to his children on the phone that night.

“My son told me he drowned and my son told me he was unconscious,” she said. “I was very depressed, still in shock.”

The next morning, Rai had seen the video of the rescue that has since caught the attention of President Donald Trump.

Ryder Williams, 16, the lifeguard who saved Nathaniel, said he saw the boy lose his balance in ankle-deep water. He called on the radio and then ran towards Nathaniel.

“After the first wave, I couldn’t get it out because it was limp and the waves were pushing too hard,” he said in a statement.

California State Parks, which employs lifeguards at that beach, said the boy was dragged about 15 yards (13.7 meters) into the ocean before the lifeguard made contact with him.

In the video, Williams can be seen diving into an oncoming wave while hugging the child.

Another lifeguard jumped in to help, along with some bystanders, who Williams said he warned to return to shore.

“I am grateful to have had the opportunity to return the child safely to his family,” he said. “This is my job and I love what I do. I am grateful to my fellow lifeguards who perform rescues like this every day.”

The boy did not suffer serious injuries and, after a medical evaluation, was released to his family, California State Parks said in an emailed statement.

Rai said her son told her he had sand in his lungs and was coughing it up after reaching shore. Now his son, who is expected to return from California in a few days, is dealing with the psychological effects of what happened.

“He’s still been thinking about it a lot. It’s on his mind,” he said. “It bothers him when he sleeps. So it’s obviously traumatizing.”

Rai approached Williams and told him he hopes to thank him directly.

“What he did, I can never repay,” he said. “I will be eternally grateful.”