CAMP BAHARIA, Iraq -- The lake’s still waters and the quiet ambience of the early evening hours of June 12 seemed to contrast with the remembrance of a fallen warriors’ bright nature. As the sun’s light graced the Iraqi skies for a few last hours that day, Marines and sailors from 1st Battalion, 6th Marine Regiment and 2nd Platoon, Company A, 2nd Combat Engineer Battalion, commemorated the falling of their own rays of sunshine, Lance Cpl. Mario A. Castillo and Lance Cpl. Andrew Kilpela. Castillo, a 20-year-old Brownwood, Texas native, known as ‘Happy’ by his fellow engineer platoon members, was killed in action alongside Kilpela June 10 when an improvised explosive device detonated near their vehicle. The Brownwood High School graduate, other engineers and several infantrymen had been patrolling through a roadway outside Fallujah, posting signs that warned the local populace to beware of insurgent-emplaced IEDs in the area. Two days later, hundreds of his brothers-in-arms gathered at the water’s edge outside Baharia’s chapel to celebrate the life their friends had lived among them. Chaplain Richard Ryan commenced the memorial service with a prayer, after which unit commanders spoke words of encouragement. “To the members of his platoon, Castillo was known as a Marine who never complained, who always had a smile on his face, and whose positive attitude was infectious,” stated Capt. Waheed U. Khan, Headquarters and Service Company, 1st Battalion, 6th Marine Regiment company commander. “Let’s remember ‘Happy’s’ infectious Cheshire cat grin he always had,” added 1st Lt. Robert E. Spalla, Castillo’s platoon commander. His fellow engineers also celebrated the levity and happiness Castillo brought to whatever task he did. “‘Happy’ never failed to relieve our stress, no matter what happened or how aggravated I became. ‘Happy’ was always there with a smile to say something funny to make me laugh and put it all behind me,” explained Cpl. Allen Ryals, Castillo’s squad leader. “June 10, 2005 is a day that will remain infamous to all of us here today. For the Marine Corps, a great Marine has fallen. For our battalion, a great engineer asset has been taken. For us at Alpha Company, 2nd Platoon, we have been shorted a brother, one of our closest friends.” Lance Cpl. Marco Martinez, Castillo’s team leader, then approached the podium to read a self-written poem commemorating the fallen and deliver some final words. “‘Happy’ was a guy who always looked out for everyone else. I remember, one time, I asked Cpl. Ryals for the matches out of his MRE (Meal Ready-to-Eat field ration), and ‘Happy’ said, ‘Oh, Marco, I got you.’ He pulled out a book of matches and said, ‘Here, I knew you would need these.’” 2nd Platoon Marines also remembered Castillo for his dedication to duty. “He was a guy you couldn’t ask anything more of, who always gave 100%,” added Martinez, who had served with Castillo since June 2004. “We would volunteer to do missions and he never complained. He was motivated and proud to be doing his job out there.” Castillo’s dedication was not for the Marine Corps alone, however. “’Happy’ was real big into his marriage and his family,” Martinez said. “He loved his wife, and always worried about her being happy. We’d go over to his house, and he’d cook up food and throw parties for the whole platoon. He never asked for anything in return.” After a few final prayers, 1st Sgt. Alex Dobson took the stand to call role. Upon shouting out each name, Castillo’s squad of engineers answered with calls of ‘Here, first sergeant.’ “Lance Cpl. Castillo. Lance Cpl. Mario Castillo. Lance Cpl. Mario Alberto Castillo,” Dobson called out, only to be answered by silence. The bugle melody of ‘Taps’ played to honor the fallen, as Castillo’s fellow Marines saluted. The congregation then silently filed out to pay their final respects, passing by each Marine’s gear display. At the base of Castillo’s ballistic vest, helmet, rifle, boots and flag lay a lone yellow smiley face rubber ball to commemorate his chipper nature. The engineers then left, and prepared to resume their counter-insurgency operations against those who had claimed their friend’s life. They kept their fond memories of Castillo ever-present in their minds, as was evident even in their living quarters. On the bed where once lay the good-natured Castillo now rests a plain white mattress, draped with a small flag and a small, yellow smiley face ball on top. “We’ll do everything we can to have his memory live through us as brothers, engineers and Marines,” Ryals said. “He will be watching us as he stands watch in that post in the heavens above.” Castillo is survived by his wife, Angela; mother, Maria; and father, Guadalupe.