Minutes before the Marine Corps charity run began, a nearby garbage can exploded near the course -- leaving a logistical delay to potentially be the difference between life and death for runners.
"If it was just a matter of minutes, in terms of difference, there would have been a good number of people running past that explosive device" because of its location along the race route, Ocean County Prosecutor's Office spokesman Al Della Fave said.
Ultimately, officials said Sunday, there were no injuries caused by the explosive device, which is said to resemble a pipe bomb. Local authorities are now investigating the incident to see if it was a terrorist act.
Investigators discovered three similar devices wired together near the boardwalk, authorities said. Two federal law enforcement officials told CNN the devices appeared rudimentary and had some type of timer.
Only one of them detonated, they added.
Just after the explosion, Della Fave said, police locked down the area near the garbage can and deployed bomb detection dogs. He said no additional devices were found after the dogs completed their sweep.
Race officials and local authorities canceled the event, organizers said.
"It is a real shame that that charitable run that does so many great things for the Marines is now canceled," Della Fave said. "There's no word on when it will be rescheduled, but that's where we're at right now."
'No stone left unturned'
Investigators said they found similarities between this device and the bomb that exploded in New York's Chelsea neighborhood
The devices in New Jersey and New York both used cell phones as timers, officials told CNN. Authorities said that whoever made the bombs had limited experience, given that the devices in New Jersey and the one in New York failed to work as designed.
For now, though, they do not think the two explosions are connected.
The FBI's Joint Terrorism Task Force is leading the investigation, with help from other federal, state and local officials. The Department of Homeland Security also plans to help with the investigation.
"We're out there conducting interviews, we're out there securing evidence and we're making sure there is no stone left unturned," said Brad Cohen, acting special agent in charge of the Newark FBI office.
"We were lucky'
Bomb experts will analyze the device and how it was made, according to CNN senior law enforcement analyst Tom Fuentes.
"It could be somebody that has grievance against the US military, possibly the Marine Corps specifically, and have nothing to do with an overseas-inspired attack like ISIS. So it still could be terrorism without being international, without being al Qaeda or ISIS or another affiliated group."
The bomb along the race course conjured memories of the Boston Marathon bombing. Three years ago, on April 15, double bombings near the finish line
left three people dead and more than 250 others wounded. A fourth person, an MIT police officer, was killed three days later during a manhunt for the bombing suspects.
Bombing suspect Tamerlan Tsarnaev died from gunshot wounds after his brother ran over him in a shootout while trying to escape. His brother, Dzhokhar Tsarnaev, was found guilty of 30 counts related to the bombings and sentenced to death.
"We were lucky," a law enforcement official said about the New Jersey blast.