Totally demoralizing, which of course was the point. They’re not sure yet what caused it, but:

One politician said the attack was carried by a suicide bomber.

“I am standing now at the site of the explosion and looking at the severed legs of the person who carried out the operation,” he said…

Dozens of people were injured – some critically – as the blast tore through a cafeteria while lawmakers were eating lunch.

Mohammed Awad, a member of the Sunni National Dialogue Front, was killed, according to the leader of the party, Saleh al-Mutlaq. A Shia MP also died.

They had a hot tip something was up, too, because security was using bomb-sniffing dogs at the entrance to the building, which apparently rarely happens.

What they’re trying to do here, very clearly, is show the surge isn’t working by demonstrating that even the safest part of the city is more vulnerable than it’s been. That’s why they’ve been focusing more on the Green Zone in the past few weeks. It started with the rocket attack during Maliki’s presser with Ban Ki-Moon, then another rocket attack killed an American soldier, then they found two suicide vests somewhere in the area. The fact that the bomber attacked in the cafeteria instead of the main assembly hall, where he could have done a lot more damage, makes me think he was probably a menial employee, not someone in an MP’s security detail (although I wouldn’t be surprised if I was wrong). Assuming they did a diligent job with the dogs as people were coming in, it also means the bomb was hidden somewhere in the building before the doors opened this morning.

The irony? Iraqi government officials complained last week that they were tired of unnecessary searches inside the Green Zone.

Updates will be coming, I’m sure. Standby.

Update: The Daily Mail has photos of the bridge destroyed by a truck bomb in northern Baghdad. According to the AP, AQ’s been planning to attack bridges for awhile now.

Update: Condi Rice and McCain are talking about this now. She looks shaken.

Update: If there’s a rational motive to the bridge bombing, it might be a way to keep Shiites from pushing Sunnis any farther out of the city:

The river now serves as a de facto dividing line between the mostly Shiite east and the largely Sunni west of the city, a reality of more than a year of sectarian fighting that has forced Sunnis to flee neighborhoods where they were a minority and likewise for Shiites.

Update: Looks like I was wrong, sort of.

An official at the Ministry of the Interior told TIME that the bomber was wearing a suicide vest and was a guard for one of the members of parliament

The metal detectors at the entrance to the Baghdad Convention Center, where Parliament is housed, were not operating Thursday, said the Interior Ministry official, who was suspicious of a wider plot. Two weeks ago, Coalition forces found two suicide vests inside the Green Zone and there was speculation about the presence of a third in the area…

Within an hour of the explosion, a message from the al-Qaeda-controlled Islamic State in Iraq was posted on a prominent militant website, muslm.net, calling the blast a “message” to anyone who cooperates with “the occupier and its agents.” It said ominously, “We will reach you wherever you are”

Read the end of this post from a few weeks ago about Iraqi MPs’ ties to terrorists. And remember that the assassination attempt on deputy PM Salam al-Zubaie was also by one of his bodyguards, an ex-jihadist who he tried to rehabilitate by adding him to his security detail.

Eason Jordan notes at Iraqslogger that while American troops control the entrances to the Green Zone, Iraqis control the entrance to the parliament building itself. Wider plot indeed.

So where are the gaps? How could this happen?

First, any insurgent or insurgent sympathizer who snags a credental for fast track access around or through security checkpoints would be an extreme risk…

Second, thousands of Iraqis have less privileged credentials that provide access on a somewhat more restricted basis.

Falling into this category would be low-level Iraqi officials, Iraqis working for the coalition or contractors, parliament building janitors and cafeteria workers, and the cafeteria’s suppliers of food and drink.

He notes in passing that 15,000 Iraqis live inside the Green Zone.

Update: The death toll now is eight.

Update: Al Hurra’s cameras were on the scene and rolling when the bomb went off. Have a look.

Update: Writing at PJM, Omar Fadhil says he isn’t surprised this happened given the MPs’ whining about security measures inside the GZ.