A fight between a boss and her employee turned violent Thursday morning.

Investigators said when the boss arrived, she faced a hail of gunfire. Miami Gardens Police later identified the shooter as Guadalupe Hernandez, 59.

“She runs outside, going after the lady when she parked. And as soon as the other lady parked, she started discharging her gun,” said security guard Eddie Hernandez.

Eddie Hernandez said he’s known Lupe for several years and was shocked when the bullets began flying. A few seconds after the shots rang out, the intended target, Lupe’s boss, came screaming into the building.

“She was hysterical,” Eddie Hernandez said. “She was saying, ‘Lupe’s got a gun, she’s trying to shoot me. Lupe’s got a gun, she’s trying to shoot me.’”

Eddie Hernandez continued, “I tell her keep on running, don’t stop until you get to your office and lock yourself up and that’s when I looked and see Lupe is coming into the front door with her gun in her hand.”

Eddie Hernandez said he immediately tried to get everyone else arriving at work out of harm’s way, and that’s when he said he saw Lupe trying to reload.

“She was trying to click the gun back and she was trying to reload,” Eddie Hernandez said. “When she was inside the lobby, when she was trying to reload, the other gentleman in the lobby came up behind her, grabbed her hand with the gun and with the other hand was able to strip the gun away from her hand.”

Still, the question no one can answer is what caused the shooting.

Lupe’s husband Raul Fernandez was shocked when he heard his wife of 24 years was under arrest.

CBS 4′s Ted Scouten asked him, “What happened today?”

“I don’t know,” he said. “For me, the only thing I can figure out is she lost her mind.”

Raul Fernandez said his wife is diabetic. He wonders if a spike in blood sugar may have caused the violence.

He said Lupe and her boss have had differences for a long time and just last night, Lupe was talking to a friend, afraid she was going to lose her job.

“She was crying talking on the phone,” he said. “She was saying she was afraid she’d fire her.”

The building is home to several businesses, including Metro Traffic.

After the incident, Metro Traffic’s employees moved to a new location, though some of the employees are still working out the building.