Like the Le Mans circuit, which also ran on public roads, Spa became notorious for fatal accidents. At the 1960 Belgian Grand Prix, two drivers, Chris Bristow and Alan Stacey, were killed within 15 minutes (although Stacey's accident was caused by a bird hitting him in the face) and Stirling Moss had crashed at Burnenville during practice and was severely injured. When Armco crash barriers were added to the track in 1970, deaths became less frequent, but the track was still notorious for other factors. The Ardennes forest had very unpredictable weather and there were parts where it was raining and the track was wet, and other parts where the sun was shining and the track was completely dry. This factor was a commonality on long circuits, but the unpredictable weather at Spa, combined with the fact that it was a track with all but one corner being high-speed, made it one of the most dangerous race tracks in the world (if not the most). As a result, the Formula 1 and motorcycle Grands Prix and 1000 km sportscar races saw smaller than usual fields at Spa because most drivers and riders feared the circuit and did not like racing there. Multiple fatalities during the 1973 and 1975 24 Hours of Spa touring car races more or less sealed the old circuit's fate, and by 1978, the last year Spa was in its original form, the only major races held there were the Belgian motorcycle Grand Prix and the Spa 24 Hours touring car race; the 1000 km World Sportscar Championship race no longer took place after 1975 and did not come back until 1982.