The Wuhan Institute of Virology, linked (not surprisingly) to the PLA, is located in Wuhan. Perhaps accidentally, on purpose release of two pet projects by PLA scientists. (Or maybe just someone forgot to shut the door when they were leaving the building.)
The clock went red, but somebody escaped from the virology lab into greater Wuhan anyhow.
Just two maybe all has been released? Imagine was the slower viruses and weapons can do in a weakened population.