Officials say there is no known cause

Something went boom in the night Tuesday, but no one seems to know what it was.

The boom seemed especially powerful along the coast, where residents reported windows, doors and houses shaking at about 10 minutes before 8 p.m.

There was speculation that the sound and accompanying sensation came from a supersonic jet, officials with the Federal Aviation Administration and the U.S.Geological Survey said Wednesday.

Navy officials said they knew of no aircraft activity Tuesday night that might have caused the boom. Marine officials said they would research whether their aircraft might have been responsible.

"The only kind of aircraft that can fly at supersonic speeds are military aircraft," said FAA spokesman Ian Gregor. "Typically, when military aircraft are going that fast, they're flying in military airspace off the coast, not in civilian airspace ---- so we're not talking to them."

On Wednesday morning, Carlsbad police and fire officials said they had no information about the boom.

A deputy with the Sheriff's Department's rail enforcement team said his unit had not been notified of any railway incidents that might have caused the sound.

The FAA didn't record any events that would be related to the boom, Gregor said.

But he noted similar booms were reported earlier this year.

There is speculation that booms felt March 3 in Orange County and March 4 along the Central California coast were sonic booms from military jets, Gregor said.

Comment: Yes, speculation, only. You can read about the two sonic booms felt, and heard, 12 hours apart in California here.

Because Tuesday's boom was reminiscent of the sound and feel of an earthquake, people have been calling the U.S. Geological Survey, which monitors seismic activity. There was nothing to suggest an earthquake occurred.

Robert Dollar, a USGS seismologist, said he's not surprised to hear that many of the people who reported the San Diego County boom lived in coastal communities.

"Oftentimes, what happens is there's an aircraft that's flying out over the Pacific some place, and the boom bounces off of the water or the upper atmosphere and comes down on the coast," Dollar said. "Assuming it is a boom."