Let's also include the name of one of the all-time greats, Jim Clark, who helped revolutionize Indy car racing by bringing the rear-engine design with Lotus here. He was killed in 1968 during a Formula 2 race at Hockenheim.
Here's something interesting for this thread. The 5 tracks worldwide with the greatest number of deaths:
56 at Indianapolis
48 at Nurburgring
30 at Monza
24 at Daytona
24 at LeMans