1.   Another machine tests the performance of luggage screeners, throwing fake images of guns and bomb parts on video screens to see if they are detected.

2.   In these tests, metallic bomb parts are thrown together explosively, liquefying while releasing small amounts of nuclear energy.

3.   Prosecutors contend the calling card left electronic tracks tying McVeigh and Nichols to a nationwide hunt for bomb parts.

4.   Rob Markson, president of Action Machine in Glendale, says military contracts for bomb parts have kept his tiny shop humming since February.

5.   Shrapnel, debris, shell casings and bomb parts litter the landscape, along with the rusty remains of vehicles used as targets.

6.   The corpses showed what happened when the bomb parts shredded them alive.

7.   There is also a tentative deal on Americans helping Russians dispose of weapons-grade plutonium, a measure designed to choke the black market for nuclear bomb parts.

8.   Police said they seized several grenades, dynamite and other bomb parts.

9.   All schools were closed until further notice, and police searched for still-live bomb parts.

10.   But he said a team of investigators never found any bomb parts or explosive residue, making it impossible to determine from physical evidence how the blast was detonated.