Heroes come in all forms, and these 10-year-old twin boys are no exception after performing life-saving CPR on their dad.

Bridon and Christian Hassig were at the pool with their father, Brad, and their 11-year-old friend Sam when Brad suddenly lost consciousness while swimming.

"It was a typical afternoon—we had music on the speakers and I was doing breathing exercises underwater to relax," Brad tells TODAY. "I wasn't pushing myself or trying to be a Navy Seal."

Unfortunately, he went underwater after he went unconscious. Bridon and Sam noted Brad was slumped over and called Christian over, and he put on his goggles and dove underwater.

Related: A drowning investigator’s plea to parents about water safety goes viral

"Christian said I was on my side and shaking and my head was turning blue," Brad said. "He yelled for Bridon and Sam to jump in and they each grabbed a shoulder and pulled me to the stairs."

The boys tried to get help from their neighbors, who weren't home. Fortunately, Christian was able to get the attention of a nearby driver, who then called 911. Bridon began performing CPR on his dad based on what he learned from movies like The Sandlot and Hook.

Eventually, a neighbor of the Hassigs—who is a cardiologist—heard the ambulance sirens and ran to their backyard and dragged Brad's body from the pool steps to the deck. When Brad came to, he coughed up blood, foam and water—likely due to the natural mucus contained in our lungs that mixes with the water and air a drowning person can inhale.

Brad told TODAY that he as he was regaining consciousness, he heard his son Christian saying, "Daddy come back. You have to be OK."

Related: Teens are the second most at-risk age group for drowning

Once he was at the hospital, Brad was diagnosed with hypoxia—low levels of oxygen in your body tissues. Hypoxia can cause confusion, restlessness, difficulty breathing, rapid heart rate, and bluish skin. After spending 24 hours in the cardiac intensive-care unit, he was also diagnosed with pulmonary edema—a condition caused by too much fluid in the lungs—and shortness of breath.

He vows never to swim alone again and to keep his exercises above water.

"I'm so proud of my boys," he said. "I tell them, 'Remember you guys are heroes' and I will be grateful to them forever. And Sam is such a kind and gentle kid. It's a bond now."

What drowning really looks like

According to the Divers Alert Network, this is what to know about drowning.

  1. Except in rare circumstances, drowning people are physiologically unable to call out for help. The respiratory system was designed for breathing. Speech is the secondary or overlaid function. Breathing must be fulfilled before speech occurs.
  2. Drowning people’s mouths alternately sink below and reappear above the surface of the water. The mouths of drowning people are not above the surface of the water long enough for them to exhale, inhale and call out for help. When the drowning people’s mouths are above the surface, they exhale and inhale quickly as their mouths start to sink below the surface of the water.
  3. Drowning people cannot wave for help. Nature instinctively forces them to extend their arms laterally and press down on the water’s surface. Pressing down on the surface of the water permits drowning people to leverage their bodies so they can lift their mouths out of the water to breathe.
  4. Throughout the instinctive drowning response, drowning people cannot voluntarily control their arm movements. Physiologically, drowning people who are struggling on the surface of the water cannot stop drowning and perform voluntary movements such as waving for help, moving toward a rescuer or reaching out for a piece of rescue equipment.
  5. From beginning to end of the instinctive drowning response, people’s bodies remain upright in the water with no evidence of a supporting kick. Unless rescued by a trained lifeguard, these drowning people can only struggle on the surface of the water from 20 to 60 seconds before submersion occurs.