SEABROOK, N.H. – One moment, Matt Tomaszewski was enjoying a sunny day at the beach with his family. The next, he was running to the ocean with his paddleboard to try to save the lives of six swimmers caught in a rip current.

He was among numerous good Samaritans and others who sprang into action Sunday at New Hampshire’s Seabrook Beach. Police and fire rescuers were called. One officer shed his uniform, jumped in and helped swimmers to shore; he returned later with a surfboard to search for another. Lifeguards at a nearby beach swarmed in on Jet Skis and with a rescue boat.

Matt Tomaszewski and his 17-month-old daughter, Chloe. Tomaszewski’s family was visiting his parents in New Hampshire when he dashed into the water to save people caught in a riptide.

Four swimmers and a good Samaritan who also got caught in the current were pulled to safety, but a married couple died.

Tomaszewski, a 29-year-old former basketball player for Syracuse University, managed to help two people grab his board. He also tried to rescue a third person who appeared to be unconscious.

He “helped to get his head out of the water and tried to put as much of his torso on the paddleboard as I could while the other two were just holding on,” Tomaszewski said.

But then, a wave pushed the man away, and he lost sight of him. He gave his board to the other two swimmers who headed to shore as he went in search of the third swimmer.

“I learned afterwards that the people I helped have three daughters, and I’m a father myself, so when I was running out there, I was thinking about saving as many people as I can. And on my way back in, it was all thinking about my family,” Tomaszewski, of Boston, told WCVB-TV.

A husband and wife, 49-year-old Michael Cote and 47-year-old Laura Cote, of Methuen, Massachusetts, were pulled unconscious from the water and died, police said.

“They were so involved in every spiritual and other undertaking in this parish that many of us are in deep mourning,” the Rev. Sean Maher, of St. Francis Parish in Dracut, Massachusetts, posted on Facebook. A service for them was planned Monday night.

Fred Marion and his wife attended church with the Cotes. They vacationed with them in the mountains of New Hampshire and traveled together to Washington, D.C., and Rome.

“Certainly them being friends, it’s stunning that this happened,” Fred Marion said. “We are in shock, as anyone would be.”

The five people who were rescued were unscathed.

Rip currents, sometimes referred to as riptides, are narrow channels of water that move as fast as 8 feet a second and occur at any beach with breaking waves. They move away from the shore. Anyone caught in them is advised to swim parallel to shore to escape their pull.

There were signs on the beach warning swimmers that no lifeguards were on duty, but not about the potential for a rip current, Seabrook Town Manager William Manzi III said.

It was the first one he could remember since becoming town manager five years ago. Alerts on the rough currents and an advisory to avoid swimming were put on the local police department’s social media accounts afterward.

The police and fire departments are expected to issue recommendations in response to the tragedy in the coming days, to be considered by the town board, Manzi said.

“Whatever they recommend, we will take a look and see what happens,” Manzi said.

In 2006, New Hampshire beaches started a flag warning system after two swimmers drowned in rip currents near Hampton Beach the year before. The color-coded flags included green ones to signal low risk and red to alert beachgoers to high risk conditions.