You may be correct as you are the second to mention the almond-like smell.
Googling I found this incident from 2002 that reminds me of the boys at OU in the underground tunnel with the vial.
12 Mar 2002
Man Arrested For Possession of Cyanide In Chicago
CHICAGO, IL: A man who was arrested on Saturday night was formally charged on Monday with storing deadly powdered cyanide in an underground passage that makes up part of the city's mass transit system. The suspect is said to had taken over a Chicago Transit Authority storage room under the downtown district and stored sodium cyanide and potassium cyanide there. University of Illinois-Chicago police arrested the suspect and a juvenile on Saturday night for allegedly trespassing.
According to an FBI affidavit filed in federal court, the two people were found in a steam tunnel under the university's education building. The FBI said the man was wanted on charges of fleeing to avoid prosecution in Wisconsin after failing to appear on charges in Door County alleging vandalism against utility systems that knocked out electrical power to a town of 9,000 people. When he was arrested, the suspect was carrying a vial containing a powder that was determined to be sodium cynanide- sodium carbonate.
The juvenile told FBI agents that the man had taken over an area within a CTA underground passageway to store chemicals. The man was interviewed on Saturday night and admitted that he had keys to various CTA sub-stations. Local news reports said the man thought of himself as a self-styled "anarchist" (domestic terrorist) and used to hang around with computer hackers, using the screen name "Dr Chaos."
EERI HAZMAT