WASHINGTON — A former University of Massachusetts Amherst swimmer and Westfield High School graduate died earlier this month trying to rescue a teammate in the Arabian Sea.

Under the darkness of night on Jan. 11, in the roiling high seas off the coast of Somalia, members of the U.S. Navy’s SEAL Team 3 began to climb aboard an unflagged ship that was carrying illicit Iranian-made weapons to Yemen.

The team included Navy Special Warfare Operator 1st Class Christopher J. Chambers, 37, the UMass student who graduated from Westfield High in 2005.

As Navy Special Warfare Operator 2nd Class Nathan Gage Ingram began climbing the ladder onto the boat, he slipped, falling into a gap the waves had created between the vessel and the SEALs’ combatant craft. As Ingram went under, Chambers jumped into the gap to try to save him, according to U.S. officials familiar with the incident.

It was an instinctive act, honed by years of training, one teammate going to another’s aid. But weighed down by their body armor, weapons and heavy equipment, the two SEALs plunged into the depths of the Arabian Sea and died, said the officials, who spoke on condition of anonymity to provide details of the Jan. 11 raid.

The mission came as the interdiction of weapons to Yemen takes on new urgency. The Yemen-based Houthis have been conducting a campaign of missile and drone attacks against commercial and Navy ships in the Red Sea and Gulf of Aden over Israel’s war on Hamas in the Gaza Strip. And U.S. retaliatory strikes have so far not deterred their assaults.

The 11-day search and rescue mission to locate the two SEALs was called off on Sunday and became a recovery effort. And on Monday, the Navy released their names, after their families were notified.

“Chris and Gage selflessly served their country with unwavering professionalism and exceptional capabilities,” said Capt. Blake Chaney, commander of Naval Special Warfare Group 1, which oversees SEAL Team 3. “This loss is devastating for NSW, our families, the special operations community, and across the nation.”

Chambers was a successful swimmer in high school and at UMass Amherst. According to his bio on the UMass Amherst Swimming and Diving team’s website, he moved with his family from Maryland to Massachusetts prior to his junior year of high school.

Chambers graduated from Westfield High in 2005, and he was the 50-yard freestyle state champion as a senior. He was also a member of the National Honor Society, the UMass bio states.

He transferred from UMass to the University of Maryland after his sophomore year and swam for that school as well.

Chambers enlisted in the Navy in 2012, and graduated from SEAL training in 2014. His awards include the Navy/Marine Corps Achievement Medal with Combat “C” and three Navy/Marine Corps Achievement Medals. Ingram, 27, of Texas, enlisted in 2019, and graduated from SEAL training in 2021.

Heroics praised

On Tuesday, Massachusetts Gov. Maura Healey and of Veterans Services Jon Santiago issued statements.

“In his heroic life and tragic passing, we recognize the ultimate example of the sacrifice that every servicemember and veteran has offered on behalf of our country,” Healey said. “We are more determined than ever to honor that sacrifice in our actions as well as our words. I’m keeping the Westfield community and all who knew Chris in my thoughts as Massachusetts mourns another tragic loss, and my heart goes out to all of our heroes who serve and our military families.”

Santiago said, “In the face of an unthinkable tragedy, our Massachusetts veteran community comes together to mourn the passing” of Chambers. “My heartfelt sympathies go out to his family, friends, and fellow sailors who are grappling with this tragic loss. To all who knew Chris, we can’t begin to understand the unimaginable pain you are facing, but we’re committed to honoring his legacy.”

At the White House, President Joe Biden said in a statement that, “Jill and I are mourning the tragic deaths of two of America’s finest — Navy SEALs who were lost at sea while executing a mission off the coast of East Africa last week.” He said the SEALs represent “the very best of our country, pledging their lives to protect their fellow Americans. Our hearts go out to the family members, loved ones, friends, and shipmates who are grieving for these two brave Americans.”

The U.S. Navy’s 5th Fleet is conducting an investigation into the incident. That probe is expected to examine whether the SEALs were properly equipped and trained for the mission, whether procedures were followed, and any decisions regarding the timing and approval of the raid, including the weather and the state of the seas.

According to officials, the commandos launched from the USS Lewis B. Puller, a mobile sea base, and they were backed up by drones and helicopters. They loaded onto small special operations combat craft driven by naval special warfare crew to get to the boat. It was the type of boarding for which SEALs train routinely, and illegal weapons moving from Iran to Yemen-based Houthis have been a persistent concern, particularly as the rebels continue to target commercial vessels in the region.

The team boarding the dhow was facing more than a dozen crew members. They ultimately seized an array of Iranian-made weaponry, including cruise and ballistic missile components such as propulsion and guidance devices and warheads, as well as air defense parts, Central Command said.

The raid was the latest seizure by the U.S. Navy and its allies of weapon shipments bound for the rebels, who have launched a series of attacks now threatening global trade in the Red Sea and Gulf of Aden. The seized missile components included types likely used in those attacks.

Chambers and Ingram, who were assigned to a West Coast-based SEAL unit, “were exceptional warriors, cherished teammates, and dear friends to many within the Naval Special Warfare community,” said Chaney.