At five minutes out and 12,000 feet in the air, Remington J. Peters and the other members of his Navy parachute team began their final preparations to jump from their C-130 transport plane. At two minutes, the group members, firing one another up, huddled together and said a prayer. At one minute, they duckwalked their way to the now-open back hatch, a smile glued to Petty Officer Peters’s face.

“Of an outstanding group, he was really a standout — he had an outgoing, positive personality,” recalled Billy Hewes, the mayor of Gulfport, Miss., who jumped out of a plane alongside Petty Officer Peters during an event last month celebrating Mississippi’s bicentennial. “His SEAL team members in this elite group fed off his enthusiasm.”

That performance turned out to be one of the last for Petty Officer Peters. A special warfare operator first class, he died on Sunday when his parachute did not open properly and he plunged into the Hudson River as hundreds of people watched from Liberty State Park in Jersey City. He was 27.

His group, the Leap Frogs, was a main attraction of a Fleet Week event promoted as offering the public, especially families with children, an opportunity to learn more about the Navy, the Coast Guard and the Marine Corps.

With the Statue of Liberty and the Manhattan skyline visible in the distance, the parachutists jumped out of a helicopter around noon, spinning through the sky.

But Petty Officer Peters separated from the others, dropping out of view. His parachute, which never fully opened, fell into a parking lot. The Navy said in a statement released on Monday that it was investigating the accident and pointed to “an equipment malfunction, though the specific nature and cause is currently unknown.”

In a tribute on Facebook on Tuesday, the Leap Frogs wrote: “The members of the United States Navy Parachute Team ‘The Leap Frogs’ would like to honor our teammate and friend, Petty Officer First Class Remington ‘Remi’…