The family of one of the U.S. service members killed in the war with Iran when a drone struck a port in Kuwait on Sunday remembered him as a rock in their lives.

Spc. Declan J. Coady’s family said in a statement that he died on his way to the hospital after sustaining injuries in the airstrike in Kuwait.

“On Sunday, March 1, after trying to check in, we heard nothing. Trying to be positive we all assumed he was just in a situation where he couldn’t message back, but we all knew something was wrong,” the statement, written by his sister, Keira, said. “At 8 p.m. as we all were getting ready to go to bed, the doorbell rang, and the rest of that night will forever be one of the worst nights of our lives. While it’s all blurry, we all knew what the doorbell meant.”

Sgt. Declan Coady  U.S. Army Reserve Command

Keira remembered her brother, who was posthumously promoted, as reserved, but passionate.

“He was supposed to be 21 on May 5. He was just a baby, and will forever be mine and Aidan’s baby brother, Rowan’s older brother, and our parents’ son,” she wrote.

“He was truly a rock in all of our lives and was just the most amazing brother and son my family could have asked for,” she added.

Coady was reserved, very intelligent, and a former Eagle Scout who came from a family dedicated to service, his uncle, John Crandall, told “TODAY.”

“Whether he was quiet or whether he was talking about the subjects he loved … it’s almost like you could feel his something really good about him when you sat next to him, and it was just wonderful to be around him,” he said.

Coady, 20, followed his older brother’s footsteps in joining the U.S. Army, and had dreams of becoming an officer, Crandall said. He said Coady was an “incredibly gifted young man.”

“He was definitely highly motivated to be an important figure within the U.S. Army,” Crandall said.

He said he felt “absolute shock” when he learned of his nephew’s death.

“He is and was a kind, decent, a high level of integrity, and just an amazing person. And always remembered that he was there for us. He put himself in a position where many people will never go and he was there for us. He was there for me, he was there for his parents,” Crandall said.