In the southern Lebanon town of El Khiam, on the evening of July 25, a precision-guided missile launched by Israel exploded on a UN observer post. The structure, made mostly from cement blocks, crumbled under the blast.

Four UN personnel were killed, including a Canadian: Maj. Paeta Hess-von Kruedener. As a military observer and the senior member of 'Team Sierra', he was required to report ceasefire violations along the Israeli-Lebanese border "without bias."

He had continued his duty for almost 10 days, armed only with binoculars as the war between Israel and Hezbollah raged around him.

Some questioned whether the attack was intentional. The building was clearly marked as a neutral observer post, and had been in the town for decades. And in the hours before the missile struck, the observers had repeatedly warned the Israeli Defence Force that their attacks were coming too close.

UN chief Kofi Annan then suggested what many had wondered.

"I am shocked and deeply distressed by the apparently deliberate targeting by Israeli Defence Forces of a UN observer post in southern Lebanon," Annan said.

Two days after the attack, Hess-von Kruedener's wife took a definite stance against Israel.

"The building was clearly marked, their vehicles were clearly marked, they were clearly marked as UN observers," Cynthia Hess-von Kruedener told a news conference in Kingston, Ont. "So why were they firing on that base? ... In my opinion, those were precision-guided missiles, so the attack was intentional."

Bill Lewis of Kingston, who served at the same post in southern Lebanon in 1990-91, wrote an e-mail to CTV.ca expressing his outrage at the attack, and said only IDF forces had ever attacked him there.

"I simply cannot comprehend how precision guided munitions could be 'mis-programmed' to strike such a well established UN landmark.  Some IDF commander needs to be held accountable and we need to hear about it publicly," wrote Lewis.

"Men on OPs are simply sitting ducks. They trust the belligerents to respect their unarmed status.  Through all the wars that have swept this area, UN facilities have been damaged and destroyed.  OP Khiam was completely destroyed in a previous invasion, however the UNMOs survived because they were in the shelter (bunker).  No bunker on any OP could withstand the impact of the hits that were suffered by OP Khiam."

Retired intelligence analyst Cpt. Brian East met Hess-von Kruedener 20 years before, when the young soldier was a militia recruit in the Essex and Kent Scottish Regiment.

Like Lewis, he considered it likely the Israelis had targeted the post deliberately. He believed the reason was information -- the UN observers were probably reporting troop movements back to the UN headquarters in New York.

"The UN is porous and the information will get back ... It's usual that anything marked secret for the UN is not that secret," Lewis told CTV.ca.

"(Israel) couldn't allow them to continue to report, especially at that specific location, being a nexus or an approach into southern Lebanon."

He also offered another reason: water. The UN observer post was located near the Hasbani River, a source of fresh water for the Sea of Galilee, which is itself the main source of potable water for Israel.

In 2002, Lebanon began a project to re-direct the water for its own use. Ariel Sharon, the Israeli prime minister at the time, had fumed that the project was grounds for war, and the river has remained a key point of tension between the two countries.

Hess-von Kruedener's own words

The week before the bombing, Hess-von Kruedener wrote an e-mail to CTV.ca describing artillery and aerial bombing he had witnessed since the fighting began.

"What I can tell you is this: we have on a daily basis had numerous occasions where our position has come under direct or indirect fire from both artillery and aerial bombing. The closest artillery has landed within 2 meters of our position and the closest 1000 lb aerial bomb has landed 100 meters from our patrol base," he wrote.

But then added: "This has not been deliberate targeting, but has rather been due to tactical necessity."

Former UN commander Maj. Gen. Lewis MacKenzie, who served as a peacekeeper in the Balkans during the chaotic early 1990s, said he considers it probable from Hess-von Kruedener's e-mail that the attack was unintentional.

MacKenzie argued 'tactical necessity' likely meant IDF was targeting Hezbollah guerrillas, who were using the observers as so-called human shields.

"Tactical necessity is the jargon we folks use; we call it veiled speech. In other words, when other people hear us say things like that, they don't necessarily understand what we're saying. It's not code, it's just 'militarese,'" MacKenzie told CTV.ca.

"What tactical necessity would indicate -- and I would say strongly indicate, almost beyond any doubt whatsoever -- is the fact that tactical necessity was the Israelis engaging Hezbollah, who were around or on (Hess-von Kruedener's) position and using it as cover, and using (the observers) as shields."

MacKenzie said such a tactic by Hezbollah was "cowardly," but works on a public relations level -- as civilians and neutral observers are killed, the enemy begins to lose any moral authority in the fighting.

He added that armed UN troops could have warned Hezbollah to leave the area or be fired upon -- but the UN personnel at the observation post were completely unarmed. As MacKenzie said, "all they had was persuasion."

He also discounted the theory that water -- namely, the Hisbani River -- was a possible reason to attack the post.

"I'm not sure that becomes important during a conflict where your number one priority is to kill as many of the enemy as possible, and lose as few of your own as possible," said MacKenzie.

"It would have to be a pretty phenomenal source for it to be a strategic objective. And I would imagine that both sides, or at least the side that owns the territory -- the Lebanese government -- would have asked the UN to move off of there so they could exploit it."

'You don't leave unarmed observers in the middle of a conflict'

For MacKenzie, the question is not whether the strike was intentional, but why the observers were still manning their post after fighting had erupted on the border.

"I would have removed them as their commander probably on the first or second day, knowing that the war had started, because they're unarmed observers," said MacKenzie.

"And if the UN had ordered me to keep them there, I would have ordered them out and tendered my resignation -- it's that serious. You don't leave unarmed observers in the middle of a conflict.

"Observer monitor minor violations of the peace agreement, like a farmer going into no-man's-land to plough a field, or somebody taking one shot at somebody. They are not  in any stretch of the imagination responsible for sitting down in the middle of the war, when they don't have a mandate - and record what's happening," said MacKenzie.

According to retired Maj. Wes Bowers, who served as a UN observer in the same area from 1989 to 1990, it was an incredibly dangerous place to be, and observers had been killed before.

Just months before he was stationed there, American Col. William Higgins, another UN observer in southern Lebanon, was kidnapped by Islamic militants and later murdered. As a result, the U.S. government had ordered the complete removal of its military personnel serving under the UN in the area.

"There is no peace between Lebanon and Israel," said Bowers.

"They've never signed a peace treaty, so technically, they're at war. When you're sent there as a military observer, you're being sent into a war zone. Canada asked us to do that on their behalf, because it's in Canada's interests to make its best efforts ... to report violations of the ceasefire line and help them maintain the peace. And sometimes that's pretty expensive in terms of lives."

Bowers recalled a night at an observation post, west of where Hess-von Krueger was killed, where he thought he was under attack by Israel.

"All of a sudden there was a blast that shook the whole building -- just knocked as off our feet," he remembered.

"We were on our backs, flat as pancakes with eyes as big as saucers, looking at the wall. It was still intact. It kind of surprised us, because the blast was so large and the shaking was so severe, that we thought there was a tank firing at the side of the building. These are just concrete block buildings. They wouldn't stand up to a tank round or artillery shell right beside them."

While the other observers waited in the relative safety of the post's bunker, Bowers put on his flak jacket and helmet and peered outside. Beneath them in the valley, Israeli guns were firing 155 mm rounds right over the post, likely targeting Hezbollah guerrillas on the other side of the hill. The force of the discharge alone had shook the building, but they had not been the target.

It was just one of many moments, he said, when he realized the danger that UN observers face, when caught in the middle of a tenuous peace agreement - an agreement that failed, and cost Hess-von Kruedener his life.