Gunfire on Capitol Hill

There are reports of shots fired in the garage of the Rayburn House Office Building on Capitol Hill. So far, it doesn't look too serious. Some wags are already at work (from The Corner):

Nothing to worry about, just Frist and Hastert shooting themselves in the foot again.

Does anyone know where Dick Cheney is?

ABC news is reporting that Congresswoman Cynthia McKinney, since she is in the Rayburn building today, is "in the mix" as a potential culprit.