The number of fires in buses, coaches and mini buses reported by fire brigades in the United Kingdom increased from 190 in 1964 to 562 in 1969 (58 fires in mini buses in 1969). Fires in Great Britain per thousand buses, coaches and mini buses licenced increased from 2.5 in 1964 to 7.1 in 1969. The most common single supposed cause is the ignition of wire and cable due to short circuits. Mechanical heat in its various forms however is the most commonly reported group of causes. Fifty-eight per cent of the fires start in the engine of the vehicle, 15 per cent inside the vehicle, 15 per cent in the wheels. Eighty-six per cent of the fires occur when the vehicle is on the road. The greatest number of fires in buses occur during the 'rush' hours. There are more fires in the summer months in buses, coaches and mini buses although in mini buses the peak is much less marked than in the other two classes of vehicle. The age of the vehicle does not appear to be an important factor in connexion with the outbreak of fire. Sixty-per cent of the fires are tackled before the arrival of the Brigade though only 35 per cent of these are successfully extinguished. There were no fatal casualties in fires in buses, coaches and mini buses and the estimated number of non-fatal casualties was only 6 in 6 incidents during 1969.