Workers at the Port of Catoosa were disrupted by a bomb threat that came from a call inside one of the buildings on Thursday.
The Rogers County Sheriff's Office said a 911 call went to Tulsa dispatch at 11:10 am. The caller reportedly said a bomb would go off inside the Linde plant within the hour.
Plant managers decided to evacuate the approximately 150 employees.
The TPD bomb squad responded and searched but found no devices.
Employees were allowed back inside around 1:30 p.m.
Investigators said the call came from an internal phone at the plant, but information technology (IT) workers can't determine which phone, and they don't have cameras on every phone at the plant.