|First episode:||"Day 5: 10:00am-11:00am"|
|Last episode:||"Day 5: 11:00am-12:00pm"|
Hangar BB (or Hangar Double-B) was a hangar located inside Ontario Airport. The hangar was closest to Gates 6 and 7 at the airport.
Before Day 5
Hangar BB was leased to an offshore company. Sometime after or before the lease began, a cache of military grade Sentox nerve gas was buried inside a sealed container under the hangar. The hangar remained vacant for 18 months prior to Day 5. ("Day 5: 11:00am-12:00pm") At some point, a keycard for the nerve gas container was given to Chevensky, who worked at Ontario Airport as a baggage claims supervisor. ("Day 5: 9:00am-10:00am")
During the hostage crisis at the Ontario Airport, a group of three terrorists (Komar, Andrei, and another terrorist) went to Hangar BB and started digging to retrieve the nerve gas. Using the hostage crisis as a diversion, the group managed to stay undetected. A fourth terrorist, Ivan Erwich, was posing as a hostage which allowed Anton Beresch to hand him the keycard that Chevensky had. ("Day 5: 10:00am-11:00am")
As the crisis unfolded, Erwich managed to slip away from the airport and head to Hangar BB. Using the keycard, he opened the container and took out the canisters of nerve gas. After loading them on a fake SWAT van, they headed out of the hangar unnoticed.
When Agent Curtis Manning saw Erwich enter the hangar on the surveillance cameras, he took a team, led by Witt, there to check it out. When they arrived, the terrorists had already left, but they managed to find the empty container as well as traces of the chemical weapons on several dead rats.("Day 5: 11:00am-12:00pm")