Iowa Code § 102.2: Authority at fires.

A fire chief or other authorized officer of a fire department, in charge of a fire scene which involves the protection of life or property, may direct an operation as necessary to extinguish or control a fire, perform a rescue operation, investigate the existence of a suspected or reported fire, gas leak, or other hazardous condition, or take any other action as deemed necessary in the reasonable performance of the department’s duties. In exercising this power, a fire chief may prohibit an individual, vehicle, or vessel from approaching a fire scene and may remove from the scene any object, vehicle, vessel, or individual that may impede or interfere with the operations of the fire department.