Here is a link to a US Chemical Safety Board video summarizing several recent lab accidents. If you have never visited or heard of the CSB, here is a link to their web site. Have a look around.
This link is to the case CSB case Study of the Texas Tech explosion with nickel hydrazine perchlorate. It has a nice illustration of the Swiss Cheese Model of safety. This model was devised by British Psychologist James T. Reason at the University of Manchester in 1990.
Lamentations on Chemistry 
Mortar + pestle + PETN-grade energetic material challenge the verb “phlegmatize.” Expensive chemical refrigerator with frost-free freezer = boom. Thermodynamics proposes, kinetics disposes, tunneling cheats. Kinetic barriers are soft – diamond abrasive, carbiding alloys.
Chemistry is inherently dangerous for exposure, process, and products – Albert Hofmann at Sandoz, TMS azide and hypertension meds, skivved Teflon tape on aluminum pipe threads. Hire the functional best, respect safety and catastrophic failure, and stop whining. Negligence is not happenstance, the universe has no diversity agenda. Entropy watches the watchers.
Incompetence should be lethal (preferably limited to the incompetent, generally not).