Lab incidents include workers potentially being exposed to prairie dogs and fleas infected with undisclosed bioterror agents, and a fluid leak that possibly contained an undisclosed "Tier 1" bioterror agent, considered among the most dangerous of all.

The first bioterror agent is likely Plague, as in the Black Plague, Yersenia Pestis. Still transmitted by fleas, and often pops up among prairie dogs in the southwest US. The second one is likely Anthrax, considered very dangerous and stable in the environment for years. Seriously, if they're going to redact the names of these biological agents, they shouldn't make it easy to guess what it is by leaving the rest of the description in. And the thought of a level 4 biological lab having technical difficulties that expose people to things like anthrax, ebola and plague is scary as hell.

Source: the veterinary public health class I took. Don't take one if you enjoy swimming in lakes or going outside in general.