Just a couple of hours earlier and it would've been the 19th century equivalent of rush hour traffic. There were people leaving work downtown (especially the mills), people coming into town to visit the banks before they closed, a large passenger train at the Omaha Depot (which was basically toothpicked) and a whole flock of people leaving the circus, which was like half a mile SE of the track.
Who knows how reliable they are, but I've seen estimates that there were at least 500 to 1,000 extra people in town that day for the circus. Some of them stuck around for a dance that was supposed to happen that night, but many had already left. The conventional story is that the toll was so high because of the circus crowd, but in working my way through the deaths, I was surprised to find that relatively few were out-of-towners. I can only imagine how much worse the situation would've been had that whole crowd still been there.
Also worth noting that there's some uncertainty to the actual toll for obvious and gruesome reasons. Incidentally, the Ward Williams store is a good example of that as well. So far, I've been able to confirm seven people who were killed there, but they were still occasionally finding bits of remains even in early July, so who knows what the real number is? The store owner and some of the others who were there claimed just after the tornado that there were "at least 20" victims, though it probably wasn't that many. At least 10 seems pretty likely though, and similar situations played out in a number of other places as well.
I doubt the actual toll was hugely different from the official number of 117, but I'd be fairly surprised if it was under 125.