“I thought it was thunder,” said one person.
“It’s definitely not thunder; too consistent. I thought it was just mining,” said another person.
“I always considered them to be sonic booms from flying aircrafts for years,” said Loring Brunius, owner of Sierra Rock Diamond Quarry.
People who live near Pleasant Valley say their days have been interrupted by loud booms, shaking the floor beneath them.
“You can feel it in the ground, no question about it. But no one’s been able to figure out why,” said Pleasant Valley resident Peter O’Grady. “I tend to hear somewhere between four to six of these things during the weekdays usually between 11 p.m. and 2 p.m.