First off, I did not know David personally. However I am very familiar with the work that he and his companions have created in recent years.
David was one of the founders of Monster Games, a small independent video game developer located in Minnesota. In 1996, David and his friends formed the company and created games based on their racing passion. To be honest, their early games were underwhelming, but soon a once in a lifetime offer came that would put David and his friends on the map.
In the mid 2000's, Monster Games entered negotiations with Nintendo of America, and became a partner of the massive company. With guidance from Nintendo's senior game developers, Monster's quality drastically improved, and they released the critically acclaimed Excite Truck as a launch title for the Wii on 2006. Since then, Monster has been strong partner of Nintendo working with the company on four different games to date.
David was Lead Programmer on many of these games, and his loss will surely be missed. He died at 38 leaving behind his wife and parents.