170. You are fighting a fire in the electrical switchboard in the engine room. You should secure the power, then take which action?

After securing power in an electrical switchboard fire, a portable CO2 extinguisher should be used. CO2 is non-conductive, minimizes equipment damage, and is appropriate for electrical fires. Water-based agents and foam pose a shock hazard and can damage equipment, while determining the fire's cause is a subsequent action.