Police are searching for the boater who they believe is behind a blast that put a crater on Fox Island off Suffolk’s South Shore.

Detectives are not ruling out the possibility that Sunday’s incident may have been a test run for something bigger. The Suffolk Police Department confirmed to News 12 on Monday that it is working with the FBI Joint Terrorism Task Force on the investigation. 

Dina Diroma, of West Islip, was one of hundreds of residents who heard and felt an explosion just before 11 a.m.

“I can't imagine if you were near the area, what would have happened to you,” she said.

Ring doorbell videos were activated by the blast, and there were dozens of 911 calls. The Town of Babylon's Public Safety Office received more than 500 calls.

“A blast that size had to be something significant because it was felt as far east as East Islip, in Sayville and as far west as…the Merrick area,” said Babylon Town Supervisor Richard Schaffer.

Suffolk police say the crater left behind was 4 feet wide and 2 feet deep.

Acting Suffolk Police Commissioner Stu Cameron says investigators “didn’t find any fragmentation” from the blast site. He was asked about concerns that it could be someone doing a "test run" for terrorist activity.

“There could be a variety of explanations, but that is a definitely a concern,” he said. “We do know that when people produce homemade explosives, very often they want to test those explosives to make sure they function as intended.”

Police have released a picture of a 23-foot boat with stripes that was seen leaving the island after the blast. They are urging the public to contact them with any information about the incident.

So far, police have ruled out a sonic boom by an aircraft or any type of aircraft emergency.

Meteorologists say the sound could have traveled as far as it did because of the weather conditions.

“In science, it's called an inversion, when we have a dense layer of clouds, a temperature inversion occurs, and the temperature of air increases with height and that can refract soundwaves back down to the ground,” said News 12 meteorologist Sam Augeri.