Nineteen staff members at the Los Alamos National Laboratory were placed on paid leave and expelled from the lab last month pending an investigation of their possible roles in recent security and safety lapses, according to the San Francisco Chronicle.

Four of the 19 suspended employees are suspected of committing safety violations. The rest are being investigated for security lapses.

The Los Alamos lab's problems stem from a workplace culture that took root years ago, according to the article. Causes include some employees' lackadaisical attitude toward security and their unwarranted confidence that the lab is too important to be shut down.

Also, a 20-year-old student intern suffered an eye injury while she was using a lab laser. It was the latest in a series of safety lapses, including one near-electrocution, lab officials said. The intern recovered enough to return to work.

Safety conditions that led to a laser operator's eye injury this summer are appalling, said one official.

A lot of people at Los Alamos are still in a state of denial, said an official. "There has been a lack of accountability, virtually a sense of entitlement that developed over the years in the culture at the laboratory. …When they did something wrong, it was 'musical chairs': They could move from one job to another (at the lab). People didn't get fired ... and that's intolerable," said another official.