The Bloomfield Copper Company, headquartered in Jefferson Heights, was an abandoned copper factory from which Cheng Zhi and his squad operated during Day 6. It was also the place where Cheng kept his hostage Audrey Raines.
Audrey Raines, in a state of deep mental trauma, spoke the word "Bloomfield" after a risky attempt to break through to her by Jack Bauer. It provided CTU with their next lead for the recovery of the stolen FB subcircuit board. Fifteen minutes before Field Unit Bravo, led by Mike Doyle, arrived, Cheng's mercenaries left the location. CTU eventually discovered that they moved to a new location from which they could stage an attack on CTU Los Angeles with a mercenary team led by Zhou Yong.