Authorities say the woman, armed with a handgun, walked into El Segundo Popcornopolis in the 1300 block of East El Segundo Boulevard just after 8 a.m. and ordered the company's chief financial officer into his office.
El Segundo Police Lt. Raymond Garcia said some people fled from the building, while others hid in the back.
"I can only imagine she was disgruntled. I don't know what drove her to this area and why she did what she did," Garcia said.
The suspect, identified as 22-year-old Leonora Banuelos, held the male CFO of the gourmet popcorn company hostage until about 11:20 a.m., when the hostage was released. About 15 minutes later, Banuelos walked out of the building and surrendered to authorities.
Police searched the building to make sure no one else was inside. A semiautomatic handgun was recovered at the scene.
Despite the ordeal, the CFO is reportedly is good spirits. Banuelos is being held on $100,000 bail.