Two Vietnam veterans looked up into the sky as soon as they heard the Huey helicopter blades chopping through the air.“That was the sound you always wished for, that things are going to get a little bit better,” said Dan Browne, 66, of South Lake Tahoe, who served as a Navy Seabee from April 1966 until January 1969. Browne took two shifts standing guard at the traveling Vietnam Memorial Wall, which came into town Wednesday afternoon.The traveling memorial, an 80 percent scale replica of the Vietnam Veterans Memorial Wall in Washington, D.C., will stay in Carson City until Sunday and be open all day and night today and Saturday and close at 3 p.m. on Sunday. The names of more than 58,000 Americans who died in the Vietnam War are on the wall.Mayor Bob Crowell and Gov. Brian Sandoval marked the official opening of the wall with a wreath-laying and a short speech by Crowell. Sandoval did not speak at the event, although he mingled with the small crowd afterward.Browne's first shift was from noon until 4 p.m. on Thursday, his second shift was midnight to 4 a.m., today.“It's no problem to stand outside here in the cold for a few hours,” he said.Browne stood guard over the wall and over the names he had already found, of three men killed by a rocket he barely avoided when he left their tent to eat breakfast. He never misses a meal, he said, motioning to his belly.“A 122-millimeter rocket hit our tent” while he was gone. “We were builders together,” he added, referring to his fellow Seabees who were part of a construction battalion. “Those guys gave the ultimate.” When Browne is standing on his late guard shift, during the dead of night, he may stare into the darkness like he did when he was in Vietnam. The wall and the guard duty bring up the memories of when he was “in country” in Vietnam, he said.He counts himself lucky that he is still be able to stare into the darkness.“We're lucky because we have the ability,” he said, motioning to the wall listing the names of his Seabee comrades and the thousands of other U.S. casualties.Friendly FireJohn Lingar of South Lake Tahoe, who served between 1966 and 1968 in the Army, looked up along with Browne when they heard the sounds of the Huey helicopter blades.The helicopters often brought them in and took them out and, for Lingar, being dropped off was the start of his connection with one of the names on the wall.It was Aug. 1, 1967, and he was sent to dig a foxhole, and two others joined him in setting up a makeshift camp. Lingar then stood guard duty, and later on woke up another soldier to take the next shift. When mortars hit, the soldier dove into a tent for cover, and a sergeant who had been sleeping in the tent, startled and not knowing who he was, shot and killed him.Tears came to Lingar's pale green eyes and his voice began to quiver“He opened up with his M16, blew him away,” he said.Lingar was wounded in the mortar attack and spent three months in a hospital. Shortly after returning to combat duty, he ended up at the same spot where he had been wounded and the other soldier killed.“The tents were still there,” filled with holes from the shrapnel, he said, adding that nearby trees were knicked and stripped bare, further evidence of the mortar attack.Three days after they found the old impromptu camp, while looking for an enemy base camp, he was shot in the shoulder and was sent to the rear. He spent his last few months in country guarding prisoners, he said.In 2004, some 37 years after his fellow soldier was killed, he had managed to find the sergeant there that night in Vietnam in 1967 and also went to a reunion in Waterbury, Conn., meeting up with 100 guys from his old unit. “They told me the story of what happened,” he said.Browne sat on a concrete bench while Lingar stood. There was a lull in the conversation, and then Browne said, “Once you're over there, you're not fighting for your country. You're fighting for your buddies. You're fighting for each other.” Lingar nodded in agreement.