A father has died after sacrificing himself to save his two teenage sons and two other swimmers from a dangerous riptide off Martha's Vineyard on July 31.

Kevin Foster, 55, of Cambridge, Massachusetts, rushed into the water when his sons, Kaden and Kenneth, began struggling approximately 300 feet from shore at Long Point Beach. Witnesses reported hearing the boys yelling for help as they were pulled out to sea by the powerful currents.

All four swimmers were eventually brought to safety, but Foster was found unconscious. Despite efforts to revive him, West Tisbury Police Chief Bradley Cortez confirmed that all available lifesaving measures were taken, but Foster could not be saved.

Foster, originally from Arkansas, was described by his family as someone who lived with kindness, generosity, and a deep instinct to help others. In an online obituary, his family stated that he "peacefully fulfilled his earthly assignment."

"He lost his life in a place that meant so much to him, surrounded by people he loved, on an Island that has given our family some of our most treasured memories over many years," the family said in a statement to The Martha's Vineyard Times. "While his departure leaves an immeasurable void in the hearts of those who loved him, his legacy of faith, excellence, love, service, and kindness will continue to live on through the countless lives he touched."

Beachgoers described the water conditions as increasingly violent throughout the day, with one witness, Kelly McNeil, stating she stopped swimming beyond 10 feet due to the rough surf.

Long Point Beach with choppy waves and sand dunes.

Onlookers were horrified as paramedics attempted to revive Foster on the beach. "When he finally arrived at the beach, I actually went over to where their stuff was and began packing it up as I couldn’t bear to watch them try to revive him," said beachgoer Lisa Conroy Murphy.

Several individuals were rescued from the water on the same day Foster died, according to the Vineyard Gazette.