Superstorm Sandy forced the cancellation of numerous business conferences and events along the East Coast last week. The common theme in the decision to curtail or cancel events was the speed with which uncertain weather conditions became unmanageable.

Some of the storm's worst devastation was in New York, where all public transportation was shut down and a state of emergency declared. On Oct. 28, New York officials ordered the evacuation of Flood Zone A, which included the area around the Jacob K. Javits Convention Center on the west side of Manhattan and the area on the southern end of the island around Wall Street.

The Javits Center was officially closed on Oct. 29 and 30, causing the cancellation of two events: the International Security Conference & Exposition (ISC EAST 2012) and the Advanced Energy 2012 Conference, both scheduled for Oct. 30-31.

JA Special Delivery (JASD) New York, produced by Nielsen Expositions in tandem with the National Jeweler brand, was scheduled to be at the Javits Center for three days, Oct. 28-30. Due to the evacuation order, JASD was cut down to just one day.

Drew Lawsky, group show director at Nielsen Expositions' JA New York Shows, said, “We made the decision to shorten the show on Saturday morning after conferring with public officials, the Javits Center and watching the updated weather reports.” By that point, most of the exhibitors were already on site. “We know of less than 10 companies that did not make it to the show,” he said.

Exhibitors reported doing brisk business during the one-day show. “Since our show has cancellation and reduction-in-attendance coverage, we are in dialogue with our insurance agent,” Lawsky said. “Like always, we will do the right thing and offer a credit on their 2013 booth fees.”

All Things D, a unit of The Wall Street Journal Digital Network, had scheduled its D: Dive Into Mobile conference for Oct. 29-30 at the Ritz-Carlton in downtown Manhattan, but announced Oct. 28 that the event would be postponed. New dates have not been determined.

Kara Swisher, who co-hosts and co-produces the conference, explained the decision on the AllThingsD website on Oct. 28. Up until the previous evening, she wrote, “New York City officials were more confident that the storm would be manageable. But by today at midday, things had deteriorated and some airline flights, Amtrak trains and even New York subway service, were being canceled.” The final decision was forced when New York Mayor Michael Bloomberg ordered the evacuation of the low-lying area of lower Manhattan, where the Ritz-Carlton is located.

The situation in New York was mirrored in many other convention venues along the Eastern Seaboard.

The Ocean City Resort Gift Expo, billed as the largest souvenir and gift show for coastal and resort retailers from Maine to Virginia, was scheduled to run Oct. 27-30 at the Roland E. Powell Convention Center in Ocean City, Md.

The first day of the show, Saturday, went forward as scheduled from 9:30 a.m. to 5:30 p.m. Tim von Gal, a partner at Urban Exhibitions, which runs the event, said in an interview, “As weather conditions and predictions worsened, town officials made the decision to close the exhibit halls of the show starting Sunday, causing Urban Expositions to cancel the remaining days.”

Although von Gal declined to provide projected or actual attendance figures, more than 450 booths were expected, according to the show's website. “All of us at Urban Exhibitions were deeply disappointed that hurricane conditions forced the closing of the show after only one day,” he said. “First and foremost, we are hopeful that our retailers have all come through this storm safe and sound.”

Exhibitors will be compensated for the lost days of the show. “Urban Exhibitions carries show interruption insurance and is in the process of filing a claim in hope that we'll be able to seek some level of reimbursement for our exhibitors,” von Gal said.

Events scheduled for later in the week were also being affected at press time, both in New York and elsewhere. For example, the National Association for College Admission Counseling postponed two events that were originally scheduled for Nov. 1, the Atlantic City National College Fair and the Boston Performing and Visual Arts College Fair.