It wasn't Zyklon-B; it was jenkem.

http://www.kvia.com/Global/story.asp?S=8017441&nav=menu193_2

EL PASO -- A foul stench and dirty water have filled the El Paso Holocaust Museum at its new location near Downtown El Paso.

Staffers there discovered a foul stench in the building and filthy water all over the floor, after a sewer main backed up this morning.

El Paso Water Utility crews said a line carrying sewage away from buildings in the entire area had clogged, possibly due to excessive grease.

Water crews are on the scene, helping museum employees with the clean-up.

ABC 7 has not yet confirmed if any artifacts from the museum were damaged.