For weeks, Bike New York has been promoting its upcoming 5 Boro Bike Tour with posters hung around the city, depicting hundreds of cyclists beginning their journey with a dramatic pyrotechnic send-off— two columns of flames reaching into the sky. Just last week, the ads raised nary an eyebrow in passersby. But following Monday's bombing of the Boston Marathon, which left three dead and more than 170 injured, Bike New York couldn't pull the ads down fast enough.

"We had these ads all over the city, and beginning today, the MTA is removing all of them," the organization's CEO Ken Podziba told us this morning, adding that the decision to pull the ads was a no-brainer. "We were getting phone calls and emails from people who thought the ads were inappropriate and we agreed. The last thing in the world we want to do is offend anybody in a time of tragedy."

The ride, to take place on May 5th starting in Lower Manhattan, means that Bike New York won't have time to pull together a different ad campaign—which Podziba said is just fine.

"It will probably be blank, which I guess is a message in and of itself," he said, referring to the spots on the subways previously occupied by the posters. "Our hearts go out the victims and their families. We're in solidarity with them." The pyrotechnics themselves will also be cancelled, though Podziba said it's too soon to know whether any sort of memorial will accompany the start of the ride.

Security throughout the city has been heightened considerably following the attacks, and beefed up police presence for the tour is all but guaranteed. Last week, a Manhattan judge ruled that Bike New York is considered a charitable organization, meaning it would not be responsible for financing the $1 million NYPD security fees.

"The NYPD has done a fantastic job securing the 5 Boro Bike Tour for the past 35 years," Podziba said. "I have no doubt that in our 36th year, they'll do everything they can to make sure cyclists, spectators and everyone else is safe."