A woman opened fire at a suburban Baltimore warehouse Thursday, killing three people before taking her own life.

The Baltimore Sun and Harford County Aegis report that Snochia Mosley was a temporary employee at the Rite-Aid warehouse near Aberdeen, Maryland, about thirty miles from Baltimore.

Investigators say employees were shot both inside and outside the distribution center. A motive for the shooting is not yet known.

The shooting is one of three to erupt in U.S. workplaces in the space of 24 hours and comes less than a year after a gunman killed three fellow employees at another Harford County, Maryland business.

Harford County Sheriff Jeffrey Gahler said the shooter used a 9mm Glock pistol. The sheriff did not identifi the victims at the time, saying the families had not yet been notified.

Ms. Mosley died at an area hospital.

A friend described Ms. Mosley as someone alienated, but not angry: “I just believe this was emotional distress. If she did this, it was her last straw.”

[Source: Baltimore Sun, Hartford County, MD Aegis]