Two weeks ago, at 7:30 a.m., Brian McCauley looked out the window of his house in a sedate neighborhood of Managua, Nicaragua.

The quiet street was filled: two National Guard jeeps loaded with .50-calibre machine guns, an armored personnel carrier and about 20 soldiers - some near the trucks, others at the swimming and tennis club down the street.

McCauley cautiously walked outside and approached one of the Guardsmen. "What's going on?" he asked in Spanish. The soldier allayed his fears: "It's nothing. Things are very quiet."

"In that case, can I go running?" McCauley asked.

The soldier nodded. "Oh, yeah," he said.

For many, the increasingly grim and bloody civil war in Nicaragua has torn their lives apart. Hundreds, perhaps thousands of Nicaraguan civilians have been killed, caught in the fighting that rages in the slums and barrios of the capital and elsewhere between President Anastasio Somoza's National Guard and the Sandinista guerrilla.

And for Americans, the war took an even more gruesome turn with Wednesday's brutal slaying of an American newsman, ABC-TV's Bill Stewart.

But for some Americans, evacuated over the the last 11 days as fighting became heavier, it has been a strangely ironic experience.

"It's scary, but it doesn't touch you," said McCauley, 38, the director of the American School in Managua, who left a week ago. His wife Helena and their 19-month-old daughter Nicole were evacuated several days before that. McCauley is staying with his parents in Riverside, Conn.

"Sometimes someone does get caught in the crossfire, but that's a matter of being in the wrong place at the wrong time," he recalled earlier this week.

McCauley had lived in Managua for a year, weathering the outbreak of civil war in September and his school's subsequent drop in enrollment from 700 to 240. Despite the fact that gunfire distantly echoed throughout the year, enrollment rose again to 500 and McCauley expected the American School to run the whole year - which it barely did.

Like many in the American community of roughly 3,000, the McCauleys lived inside a war that rarely touched their lives.

Their neighborhood, "Las Colinas," which means "The Hills," was an oasis in the fighting. Among the white-and-tan plaster ranch style houses, surrounded by the lush green of palm and mango and coconut trees, the sound of gunfire became so regular that McCauley could identify the weapons.

"The .50-calibre weapons had a deep kind of slow 'boomp, boomp, boomp' sound," said McCauley. "You knew that was the Guardia [government troops] because they had the larger machine guns.

"You'd hear those, then you would hear small arms, and then you would hear nothing. And you'd say, 'Okay, someone has won that.'

"Then you'd hear a bomb, and you'd say, 'Oh, who's that?'"

Then there were the rockets. "You'd see a flash and hear a rocket - 'boonshhh.' There were maybe 20 to 30 of those in an afternoon being fired. That's not many. It wasn't like a war movie."

During the afternoons, McCauley would often sit in his backyard and watch plane strafing an area, or small single-engine jets firing rockets. "You would see a little flash of white light and smoke," he recalled.

Sometimes after dinner he and his friends would sit on the back porch and watch the rockets go off. "There was a certain fascination," he said. "We had never heard those noises before. What else can you do? You sit and hear them. At least the more you know, the less you're frightened."

The closest his neighborhood came to actual fighting was one night a month ago, when he awoke with a start at the sound of a bazooka. "It practically blew me out of bed," he said. "It sounded like someone was trying to obliterate my mango tree."

The next morning, a friend who lived two blocks away informed McCauley that shooting had broken out in front of Nicaraguan minister Antonio Mora's house, across the street from McCauley's friend.

"My friend said Mora slept with his machine gun by his bed," McCauley said. "When Mora heard the noise, he picked up his machine gun, put on his flak jacket, and ran out and led the fight against the guerrillas.

"The next morning, Mora told my friend, 'We had quite a fight last night, but I want to assure you that things are fine. There is only one bullet hole in your house."

"I really didn't want to leave," said Helena McCauley. "The country and climate were perfect for babies to grow up in." She finally decided to go when the gunfire began to frighten her infant daughter.

She was reconiled to the military roaming their neighborhood and the streets. "You get used to it," she said. "If you don't, you shouln't go overseas."

Helena McCauley, 32, was born in Czechoslovakia, and like her husband - a former Peace Corps volunteer and world traveler - she has lived in Europe, South America and the United States. "I'd been through this before," she said.

All year long she had shopped at the central market in Managua for fruit, vegetables and other food. "People told me it was dangerous," she said. "But I never had any problems. Maybe if you're a snobby foreigner, it would be different. But I had gotten to know the people who sold us our food. They were our friends."

Still, the soldiers were everywhere. "These guys from the Guardia can be scary," Brian McCauley said. "They'd come up to you and they'd have a grenade on one shoulder and a machine gun under one arm, and they'd say, 'Who the hell are you, buddy?'

"You felt like saying, 'Gosh, I'm anybody you want me to be."

Not all their friends escaped without some incident. A couple of weeks ago, a woman who lived in the McCauley's neighborhood opened the door for a man who said he had flowers to deliver. Instead, the woman found herself face to face with Sandinistas.

"They told her they weren't going to hurt her but they put a pistol to her head," related Helena McCauley. "They took food and camera equipment." The woman was not harmed.

In the final few weeks, the war circumscribed McCauley in his neighborhood - but he still went jogging almost every day. One day, he would jog past trucks of weapons stationed in his neighborhood as soldiers fought in the barrio called Chik five minutes away. The day he left, he jogged past Nicaraguans fleeing the same barrio.

"I just felt so bad," he said. "Here I was running through this ritzy section of town, and here were these people leaving with all their possessions, their dogs, everything."

He ate dinner around 5 p.m. with six or seven other men whose families had all left by that time. "One of the few topics we discussed was politics - endlessly," McCauley said. "Somoza will win, one guy would say no, he won't. Then there would be more speculation.

"And then finally it was time for curfew, and we'd all leave around a quarter of seven. You'd go home - pack a little, look at TV a little and read. That was it. Maybe it was an adventure for five minutes of every day, but after that, you just wanted the whole thing to be over."

The remaining Americans never knew what stage the war was in. "If you listened to Costa Rica radio," he said, "you heard that 10 cities in Nicaragua had been taken. If you listened to Nicaragua radio, none of that had happened. If you wanted to know what happened in Granada, you called a friend there. But some of them were so panicked that whatever they told you was not completely accurate either.

"I never even met a Sandinista," McCauley said. So he simply listened. When the gunfire from the nearby barrio ended, and the National Guard troops were still in his neighborhood, he assumed the National Guard emerged victorious from that battle. "But you just don't ask them that kind of question - 'Who won?'"

Refugees fleeing their neighborhoods often would pass McCauley's house and ask for mangoes fallen from his trees.

"We gave them fruit, but no other food," he said. "We were all in the same boat."

Food was growing scarce because of the general business strike through out Nicaragua. But McCauley and his friends had stocked up. They kidded each other about pooling resources, most notably McCauley's Flor de Cane rum and another friend's Coca Cola.

Finally the day came when McCauley realized there was little he could do at the American School: "Not only was it dangerous to stay but everything was closed, as well."

He arranged to leave on a plane chartered by the Argentine Embassy for its personnel. Less than 24 hours after making his decision, he was airborne - en route to Panama and then Miami.

For McCauley, like most Americans and others evacuated, the only real hardship was leaving their possessions behind. McCauley left it all: his home, car, furniture and art collection, saxophone, tennis shoes, suits and, most of all, the American School.

Now safely reunited with his family in New England, McCauley is troubled by a nightmare about the murder of ABC correspondent Stewart, and he worries about the future of the school. And he already wants to return:

"You know, you look at the fields and the hills and you say, 'Nicaragua is such a beautiful country.'"