The bank robbers got away with an undisclosed amount of cash from the Bank of America when it opened Wednesday morning, but no one was injured in the robbery. No arrests had been made as of early Thursday.
A Los Angeles County sheriff's bomb squad disabled the device, but investigators said it wasn't an explosive.
The bank manager was snatched in front of her home Wednesday morning, said sheriff's Capt. Mike Parker. She arrived at her workplace wearing a device the men had strapped to her stomach.
"She was told that it was explosives and she was ordered to go into the bank and take out all the money," Parker said. "She did do that in fear for her life."
She ordered her fellow employees to remove the cash from the bank and it was thrown to the men who were waiting outside, authorities said. Parker would only say there was "a decent amount" of money at the bank and the manager did enter the safe.
The two men, who were armed with handguns and wore ski masks, took off in a two-door car and remain at large.
Parker said the woman remained inside the bank until a bomb squad arrived and removed the device from her body. The bomb squad later disabled the item with a robot. Nearby businesses were evacuated for a few hours as a precaution.
Investigators initially said they didn't believe the manager knew the robbers but they have conducted interviews to ensure she wasn't connected to the crime.
Authorities also haven't said how the bank manager was targeted by the robbers. Investigators are trying to determine if there were any video surveillance cameras that captured the incident.