A small earthquake rattled houses in Cleburne and surrounding cities Tuesday, but caused no damage or injuries.
"The first thing I thought was, 'Oh my God, somebody hit the house with a car,'" said Bobbie Johnson. "Me and my husband ran outside, and all our neighbors were on their porches yelling at each other, 'What happened? What happened?'"
Some people thought it was a sonic boom. Others thought a gas well had exploded.
"I was like, 'What was that?'" said Johnson's daughter, Jillian, 12, who was selling lemonade in the front yard.
Cleburne 911 operators were flooded with calls, especially from people living in the southern part of the city.
"A couple minutes ago, there was a big boom or whatever," City Councilwoman Gayle White told police. "It shook the chair I'm in."
"It felt just like a tremor," another woman told 911 operators. "The whole ground shook under this house."
This is the fourth earthquake in North Texas in the past year.
Experts say it's not unusual for earthquakes to occur in groups.
Recent natural gas drilling in North Texas is unlikely to contribute to tremors because the two take place at different depths, said John Holbrook, a geology professor at the University of Texas-Arlington.
"I'd rather have a tornado where you know it's coming," White said. "But an earthquake is like, 'The ground is going to open up or what?'"