This kind of list makes David Letterman sick to his stomach and question his love of auto racing.

The retired late-night comedian and IndyCar team co-owner rattles off a number racing deaths — Justin Wilson, Dan Wheldon, Paul Dana, Dale Earnhardt, Ayrton Senna, sprint car driver Kevin Ward Jr. — and wonders "maybe we've reached diminishing returns at making this sport safer."

Letterman expressed his grief in a telephone interview with The Associated Press from his Montana ranch. He spoke just two days after Wilson died from a head injury suffered when he was struck by a piece of debris at Pocono Raceway.

Letterman is part owner of the Rahal Letterman Lanigan Racing.