Trump attended the dignified transfer at Dover Air Force Base on Wednesday, where the remains of six U.S. service members killed in the crash of an Air Force refueling aircraft were returned to their families, according to the Associated Press. The ceremony came as the Pentagon investigated how the KC-135 came down during operations supporting U.S. actions against Iran.

The event marked the second time in three weeks that the president attended the solemn military ritual known as a dignified transfer since the war with Iran began on Feb. 28, the AP reported. Trump previously described the transfer process as “the toughest thing” he has had to do as commander in chief.

The AP said the dignified transfer was closed to news media coverage at the request of the families, in line with military policy. Trump spent just under two hours on the ground and did not speak to reporters as he left Air Force One and returned to it.

Alongside Trump, Defense Secretary Pete Hegseth, House Speaker Mike Johnson, and Gen. Dan Caine were present, as well as lawmakers including Sens. Tommy Tuberville and Katie Britt, both Republicans from Alabama, the AP reported. The AP also said the ceremony included the chairman of the Joint Chiefs of Staff, Gen. Dan Caine, among others.

The six service members were all assigned to Air Force refueling units and died when the KC-135 crash occurred over “friendly territory” in western Iraq last week while supporting operations against Iran, the AP reported. U.S. Central Command said the crash followed an unspecified incident involving two aircraft in “friendly airspace” over Iraq and that the loss of the aircraft during a combat mission was “not due to hostile or friendly fire,” with the circumstances under investigation. The other plane landed safely, according to Central Command.

Three of the deaths were linked to the 6th Air Refueling Wing at MacDill Air Force Base in Florida: Maj. John A. “Alex” Klinner, 33, of Birmingham, Alabama; Capt. Ariana Linse Savino, 31, of Covington, Washington; and Tech. Sgt. Ashley Pruitt, 34, of Bardstown, Kentucky, the AP reported. The AP said Klinner left behind a wife, a 2-year-old son and 7-month-old twins, and that retired Lt. Col. Ernesto Nisperos, a friend of one of those killed, sent a message describing the service members as carrying a “weight most Americans will never see” and offering praise that they acted with “professionalism, courage,” and “quiet excellence.” Nisperos also described Savino as someone with warmth and a “spark — that spice,” saying her Puerto Rican heritage and her mentorship inspired young Latinas, according to the AP.

The other three service members were assigned to the 121st Air Refueling Wing at Rickenbacker Air National Guard Base in Columbus, Ohio: Capt. Seth Koval, 38, a resident of Stoutsville, Ohio, who was from Mooresville, Indiana; Capt. Curtis Angst, 30, who lived in Columbus; and Master Sgt. Tyler Simmons, 28, of Columbus, the AP reported. The AP said Koval’s wife described him as a loving, generous “fixer of all things,” while Angst’s family described his life around service and generosity. Sen. Jon Husted, speaking on the Senate floor on Tuesday along with Sen. Bernie Moreno, said Simmons loved confiding in his 85-year-old grandmother and working out with her, according to the AP.

The crash raised the U.S. death toll in Operation Epic Fury to at least 13 service members, the AP reported, adding that about 200 U.S. service members were injured, including 10 severely, the Pentagon has said. Trump’s most recent prior dignified transfer to Dover Air Force Base, the AP said, was on March 7, when six U.S. service members killed by a drone strike at a command center in Kuwait were honored. That earlier trip included a salute as flag-draped transfer cases containing remains were carried from military aircraft to vehicles for processing at the base’s mortuary facility.