A " victim " of the brussels air raid . Gas masked ambulance men busy as bomb and gas attack is made on city . Men , women and children lay prone on the Brussels pavements when a mock aerial bomb and gas attack was made on the city to test the defences . The citizens co operated with the military authorities to make the attack as realistic as possible . Gas masked Red Cross men rushed " victims " to first aid centres , and fire fighters wearing gas masks concentrated their efforts on buildings set alight by the " bombs " . A child " victim " of the raid being rushed by gas masked Red Cross men to a first aid centre . 6 September 1934