You are part of a response team called to a building collaps…

You are part of a response team called to a building collapse that is suspected of being related to a terrorist attack. Citizens in the area are reporting victims having severe respiratory distress as they escape the building. There are many victims collapsed at the scene. There is also a report of an almond smell coming from the building amidst the severe dust. Based on these reports, which type of gas do you most suspect?