Even Fox news reported that the crowd numbered in the "tens of thousands" which agrees with the estimates made by the DC Fire-Department who would have been responsible for public safety and first-responder planning had the crowds been larger. When Fox refuses to up the ante over "tens of thousands" despite their tendency to inflate right-wing events, it's a good time to take a breath. Officials in DC said that the mall was well-occupied from the Capitol to 3rd street, which is a far cry from the crowd that attended Promise-Keepers and filled the mall back to 17th street and spilled over into the area around the Washington Monument.
If you want to trust news-outlets and spokespersons instead of public-safety officials who actually do this stuff for a living, ... fine.