SWAT members surrounded the location but weren't able to talk to anyone inside. They later rushed in. Officers found most of the hostages locked in a storage room and two others in a bathroom, police said.
The employee who was stabbed was treated and released at the scene, police said.
Police were checking to see if surveillance cameras captured the robbers on video. Investigators also were interviewing the 13 women and a man who were held hostage to determine the chain of events.
Darrow said counseling services will be provided to employees.
"Our priority right now is to take care of our employees," she said.
The store will remain closed over the weekend to give employees time to recover, and counselors will be available when it reopens Monday.