Rain continued to fall, and washed out practice on Monday (May 11). On Tuesday May 12, the 200 mph (320 km/h) barrier was finally broken in practice for the month by Danny Ongais. Mario Andretti took his final practice run of the week, and departed for Belgium. Two major crashes occurred, involving Phil Caliva and Phil Krueger.

Phil Krueger (born June 22, 1951 in Santa Monica, California), is a former driver in the CART Championship Car series. He raced in 9 seasons (1981–1986, 1988–1989, and 1991), with 23 career starts, including the 1986 and 1988 Indianapolis 500. He finished in the top ten 3 times, with his best finish in 5th position in 1988 at Michigan.

In 1984, at the 95th lap of the Michigan 500, he crashed hard in the fourth corner, which he had already spun twice before and was unconscious as the medical crew arrived at the scene, but he would return racing later. In 1988 he won the Clint Brawner Mechanical Excellence Award presented annual to the Indianapolis 500 chief mechanic who exemplifies "mechanical and scientific creativity, ingenuity, perseverance, dedication, enthusiasm and expertise" by essentially serving as his own chief mechanic and getting his 2-year old R. Kent Baker Racing March-Cosworth not only into the field, but competitive enough to finish 8th on raceday.