SAN FRANCISCO (AP) — Federal officials on Wednesday blamed unsafe working conditions and poor training for the death of a young Veterans Affairs medical center researcher in San Francisco who died after handling bacteria that causes meningitis.

The federal Occupational Safety and Health Administration found three serious violations at the lab that exposed Richard Din, 25, to the bacteria and led to his death on the way to the hospital April 28.

In particular, OSHA chided the lab for allowing Din to work with the bacteria in the open rather than in a so-called biosafety cabinet, which isolates germs behind a protective screen and provides ventilation.