According to Comeau, who went to Duesseldorf to investigate the scene, the severity of the fire and the number of casualties add up to an extremely unusual scenario. Aviation fire experts plan for large fuel fires that can enter a terminal from the airside, or, in a severe case, create a fireball on the apron that could expose curious spectators by blowing out terminal windows. Aviation standards, among them NFPA 416, Airport Terminal Buildings, Construction and Protection , plan for these risks. Fires that originate in terminals or, as was the case in Duesseldorf, on a terminal's curbside, are rarer, and seldom deadly. Comeau points out that few combustibles are used in airport construction, and plenty of exits generally allow for the safe evacuation of the predominantly able-bodied and alert people that one would expect at an airport terminal on a weekday afternoon.
Construction is of reinforced concrete.
The newer, west end of the building, Terminal C, was built in 1986 with sprinklers. Unfortunately, the fire started in the unsprinklered Terminals A and B, built in 1972. The fire was severe and unique enough to draw investigators from throughout Europe. But few had arrived by Saturday, April 13, when NFPA's Comeau teamed up with four investigators from the United Kingdom - a fire officer from Gatwick Airport, two members of the West Sussex Fire Brigade, and a police officer from the Sussex Police Department. Much of the information in the NFPA report is based on the collaborative effort of this joint NFPA-U.K. team.