The day after the Boston Marathon is like nothing we've experienced before. The FBI investigates, doctors operate, families grieve and a community tries to make sense. The daily media briefings shift our emotions back and forth from the criminal investigation to the heroes who stepped forward to save lives. Government officials try to reassure a fragile community that extra security is around "to provide comfort to the public."

But along with official calls for calm come calls of concern from out-of-town conventioneers. Event organizers spent the day meeting amongst themselves, calling Boston tourism officials and looking for reassurance that the city is safe. Law enforcement officials say it is, that only two devices exploded Monday and rumors that there were 7 unexploded bombs are untrue. Still, hundreds of people have canceled their hotel stays in Boston this week, citing "the tragedy in our area."

That tragedy played out on the doorstep of one of Boston's trade show buildings, the Hynes Convention Center. With two explosions just blocks away and Boylston Street turned into a triage center, one can imagine the anxiety felt by out-of-towners heading to the Hynes. When Boston tourism offices fielded calls today asking "what can you tell us," a common reply was, "With all the police presence, Boston is the safest city in the U.S."

The next trade show scheduled for the the Hynes carries irony, delays and, until tonight, uncertainty. The Ambulatory Surgery Center Association was set to begin registration today for 2,000 attendees but everyone was waiting all day for a final green light, which finally arrived after 6 p.m.

"After consultation with Boston officials, we are pleased to report that they recommend that ASCA 2013 proceed as planned," read a message on the event's website.

"Things are getting back to normal throughout the city," the statement read. "Media coverage notwithstanding, Boston is open for business and folks are traveling here without any trouble. We have had many folks here thank us for persevering and moving ahead with the meeting … we have been told that the streets of Boston are safe, and that the greatly heightened security presence in the area around our meeting will be very visible. For example, the Hynes Convention Center was swept by K-9 units overnight, and visitors entering the Hynes will be subject to bag searches."

The Hynes Convention Center team spent the last 24 hours reassuring and encouraging convention-goers with its own online message.

"We would like to assure our ASCA attendees that the Hynes has been thoroughly swept and is secure," the statement said. "Building staff have worked and continue to work with Boston police to keep the building safe. Your participation in ASCA 2013 will not interfere with the ongoing investigation, but WILL help Boston get right back to life. We look forward to seeing you tomorrow."

Some attendees have already made up their minds and canceled their visit. The Hynes said hotel cancelations have been "minimal" for this event.

Another Boston event may not have the same luck. A 10-minute drive away from the Hynes, and away from the crime scene, sits Boston's other trade show mecca, the Boston Convention and Exhibition Center. It's scheduled to host a big experimental biology meeting starting Saturday and all things look to be on track.

"Despite the ongoing situation in Boston, at this point the EB meeting, due to start Saturday, will go on," read a message at the top of the event's website.

But according to a hospitality professional, event attendees are canceling their hotel rooms in the Back Bay. It's not clear if these visitors booked rooms closer to the Convention Center and further from the crime scene, or if they canceled their trip to Boston altogether. But the end result shows an immediate economic concern following Monday's tragedy. One hotel has logged nearly 300 room cancellations with more than 600 other rooms at risk of cancellation.

Anxious phone calls also made their way to the Massachusetts Convention Center Authority. Mac Daniel, MCCA's Director of Communications and Marketing, says no one he knows has canceled anything. "We are re-assuring events, emphasizing security and safety protocols" in Boston and its hotels.

Words of reassurance will undoubtedly continue this week for the city, its residents and all of the bombing the victims. Later this week, President Obama is scheduled to visit Boston, where his words of comfort will ring out to Bostonians and to anyone planning to visit the city in the near future.