You could miss it in the sense that the quest objective is randomly in one of three dungeons and if you pick the right dungeon first you might not check the other two.
Thanks for clearing that up. Also, on the path to the cemetery to locate the 3 tombs, there was a dungeon with two different levels. The second level had all kinds of good gear for my level 9 wizard. Ended up getting some gear that regens health by +3 per second, a good wizard hat and a wand. Switched my gear to that stuff and was noticeably more competent moving forward to the 3 tombs. I'm brand new to Diablo so excuse my excitement over newfound beginning gear