One thing you can be pretty sure of: one day's news coverage is not the final say on any single subject. In other words, just because the media seemingly ignored your story one day doesn't mean that's the end of the story.
When it comes to media relations, there may be several reasons your story didn't gain any traction with reporters, many of which had little to do with the story itself.
You won't know for sure until you probe a bit further by calling around to see why it was that so few reporters or cameras managed to show. If it was due to competing stories or lack of resources, offer to talk with a reporter over the phone or arrange for an interview the following day.
Depending on the logistics and complexity of your event, you might also consider holding a similar event or sending out a follow-up press release a few weeks later. You just may get some interest.