I watched Carb Day and saw the Honda engine failure there. That one put a hole through the side of the block, judging by the large pool of oil it laid down in the cool-off lane. The commentators talked about it and said that Honda wanted to limit their teams' laps on Carb Day to 40 due to durability concerns, and that all the Indy engines had been built with the same suspect parts from a supplier. I was assuming that meant bad conrods or conrod bolts. But the engine failures in the race didn't result in large amounts of oil dropping out of the engines. They would be running along, then all of a sudden, they would lose a cylinder. Now I would guess broken or dropped valves.
Imagine how Fernando Alonso must feel. He came to Indy to run at the front with a Honda engine and to get a good race finish. Then his Honda engine blows up there, too. He may not want to drive anything with a Honda in it ever again. Or maybe he doesn't really care, since McLaren pays him $40M a year, and he doesn't even drive to full race distance most of the time. In hindsight, he should have done Monaco. Since it's not a power track, and the shortest race on the F1 calendar, he might have finished. Both McLaren drivers dropped out due to crashes, and Alonso actually finished the previous F1 race.