SPOKANE, Wash. -

One of the five U.S. troops who was killed late Monday evening in a friendly fire incident in Afghanistan was Sprague, Wash. Resident Justin Clouse.

Clouse was killed along with four other servicemen when a coalition jet, called in to help ward off a Taliban attack, mistakenly bombed them, an Afghan official said Tuesday.

Clouse, 22, a 2010 graduate of Sprague Lamont High School, had a couple months left in the Army. Back home in Sprague the flags are already flying at half staff as residents are grieving with the loss of one of their own.

One of those residents is Melinda Canaday, who recalled Clouse as a young man with a big heart. Her son, a senior at Sprague Lamont High School, called him "the coolest guy ever."

“Justin was a role model for kids all throughout his life. I still remember waking up early in the morning to go lift, dreaming of having muscles like him,” Canaday said, reading from a letter her son wrote for the Clouse family.

Clouse graced many pages of high school yearbook. He was a basketball star, a Most Valuable Player both on the court and in the lives of others.

“I wish I could go back and tell him that I'm proud of him and that I'm going to miss him," Clouse's coach Chad Prewitt said.

Prewitt last spoke to Clouse on Saturday and finds it hard to believe he's now gone.

“You can never judge a book by its cover because he was quiet, this big strong guy that you would think is this mean person, but man he would babysit my kids, my son. Good guy, good kid," Prewitt said.

“Justin was a brave man who was willing to risk his life for the honor of fighting for his country," Canaday said.

Clouse and the other four Americans were killed Monday night along with an Afghan soldier in Zabul province, said Ghulam Sakhi Roghliwanai, the province's police chief.

According to NATO, the troops were conducting a security operation. The service members' unit came in contact with enemy forces. That's when the casualties occurred, a U.S. military official told CNN. "There is the possibility that fratricide may have been involved," he said.

The incident is under investigation.

Roghliwanai said the troops had completed their joint military sweep at about 9 p.m. Monday (12:30 p.m. ET) when they came under rocket fire from Taliban militants.

The service members called in air support. "But the airstrike mistakenly bombed their own friends too," he said.

"The Department of Defense is looking into what happened," U.S. National Security Council spokeswoman Caitlin Hayden said. "Our hearts are heavy over this loss, and our thoughts and prayers are with the families of the fallen."

Since the Afghan war began in October 2001, 2,323 Americans have died there. Once the United States confirms these latest deaths, the number will rise to 2,328.

There have also been numerous fatalities resulting from friendly fire.

Among the more publicized ones was the 2004 death of Pat Tillman. Tillman, who became a national hero after he gave up a lucrative contract with the NFL's Arizona Cardinals to join the Army's elite Rangers force, was awarded the Silver Star, the military's third-highest combat decoration, after the Army said he was killed leading a counterattack.

Only later did the Army admit he had been shot accidentally by his comrades.

Here are some of the others:

• In April 2002, four Canadian service members were killed and eight others seriously wounded when a U.S. Air National Guard pilot dropped a 500-pound bomb on a group of Canadian troops conducting a nighttime training exercise in southern Afghanistan.

• In August 2007, three British soldiers were killed when a U.S. Air Force F-15 Eagle mistakenly struck their position with a 500-pound bomb during a firefight with Taliban fighters in northern Helmand province.

• In July 2008, nine British soldiers were wounded when a UK Apache attack helicopter mistakenly fired on them during a firefight with Taliban fighters in central Afghanistan.

• In November 2011, NATO helicopters attacked a military checkpoint in northwest Pakistan, killing 24 Pakistani soldiers. The attack wounded 13 others in the volatile region bordering Afghanistan. The incident greatly strained relations between the nations.