- You may have been looking for the novel 24 Declassified: Collateral Damage.
Collateral damage is a term which refers to the sacrifice of civilians that must be made to serve a greater good.
General Blanchard refused to fire on the chopper occupied by Jack Bauer and Ramon Salazar after the prison break because they were over downtown Los Angeles and it would cause massive amounts of collateral damage if it was to fall to the ground.
A Sentox nerve gas attack occurred on the Sunrise Hills Shopping Mall in Los Angeles, where Jack Bauer was undercover with a group of terrorists, attempting to release the gas in the mall's ventilation system. CTU called President Charles Logan, who authorized Jack to release the gas, so that they would be led to the other nineteen canisters of nerve gas, saving more lives than the 1,000 or so civilians in the mall at the time.