Mohannad al-Kaabi was risking his life to build the kind of Iraqi democracy that President Bush has called for.

He was in danger of assassination by Saddam bitter-enders. But, in fact, he was shot dead last week by a U.S. soldier in Baghdad. This disaster must be studied by U.S. planners to make sure nothing like it happens again.

Kaabi was a handsome 28-year-old marine engineer who spoke excellent English. He headed the district council in Baghdad’s huge Shiite Muslim slum of Sadr City. His council was part of a U.S. project to nurture local government.

Baghdadis have never known grassroots politics. So one early U.S. project was to set up councils in Baghdad neighborhoods. The local councils picked district councils, which in turn picked members for the Baghdad City Council.

The idea was to get Iraqis used to debating local issues — safe streets and schools, garbage collection — even if funds, and final say, still rested with U.S. officials. These councils are meant to train the new Iraqi political class — the people who will one day run for public office.

The project’s coordinator is Lt. Col. Joe Rice, an Army reservist and former mayor of Glendale, Colo., population 5,000. Rice now sits in at all Baghdad City Council meetings. He told me: “For the first time, instead of waiting for the powers that be or paying bribes, Iraqis are learning that they can suggest an idea and get something done.”

One of those who was learning fast was Kaabi.

When I met him, he was full of enthusiasm though he’d been through a bruising week. Shiite followers of the militant cleric Muqtada al Sadr had taken over the council building in his district. U.S. troops had finally evacuated the militants, peacefully.

Kaabi knew it was dangerous to work with the Americans, but he said it was in the interests of his own people. He said the militants only represented a fraction of Sadr City:

“Most of the people of Sadr City support this district council and think it comes to help them. Those who contact us can see certain changes because of what we do.”

But Kaabi was worried. “Not all Iraqis understand democracy,” he mused, as we sat in a city council anteroom. “Why? Because we are Muslims and have our special kind of (thinking about) democracy. But this new democracy comes with military and soldiers.”

Iraqis, he said, needed time to grasp how a democratic system could be brought to them by U.S. troops. He would try to persuade his constituents it was worth waiting for representative government. He didn’t falter, even after a deputy mayor of Baghdad was assassinated on Oct. 26.

At midday last Monday, Kaabi arrived to chair a council meeting in Sadr City. A jittery U.S. soldier — perhaps unnerved by the wave of car bombs — refused him access to the parking lot of the council building.

A shouting match ensued. Kaabi was shot, and he bled to death before reaching the hospital. The U.S. military say Kaabi reached for the soldier’s gun but his friends insist he did not. Advisers to the city council hoped U.S. authorities would immediately authorize a “pension” to Kaabi’s family, to show regret and prevent revenge-seeking, but three days after his death, no such authorization had been made.

It is hard to imagine a worse blow to hopes for representative government in Sadr City — whose stability is crucial to peace in Baghdad.

As the U.S. military intensifies anti-terrorist operations, one can foresee many more such errors. I want to know why Kaabi was shot and what the military is going to do to prevent future such disasters.

U.S. officials owe that information to those who are struggling to bring grassroots democracy to Baghdad.

Trudy Rubin is a columnist and editorial-board member for the Philadelphia Inquirer.