During a lavatory fire, what is the first action a flight attendant should take?

Notifying the flight deck immediately is the first action a flight attendant should take during a lavatory fire because the flight deck crew is responsible for the overall safety and operation of the aircraft. By informing them of the situation, they can assess the scenario, determine the severity of the fire, and initiate appropriate emergency protocols, including communicating with air traffic control and preparing for a possible emergency landing if necessary. This communication is crucial as it allows for a coordinated response among the flight attendants and flight deck crew, ensuring that all safety measures are effectively implemented.

The situation requires prompt and decisive action, and while other responses such as attempting to extinguish the fire, calling for passenger assistance, or preparing for evacuation are important, they should come after the flight deck has been notified. This prioritization ensures that the crew is equipped to deal with the crisis efficiently, as they may have access to systems or equipment that can help manage the fire more effectively.