Law enforcement officers and firefighters searched but didn’t find the source of a loud noise on Tuesday night. People who heard it around 9:45 said it sounded like an explosion, very close thunder or a sonic boom. The Christian County Sheriff’s Department says Nixa police, Nixa firefighters and sheriff’s deputies checked different areas in and around Nixa but didn’t find anything. The noise prompted many calls to emergency dispatchers. Some people said it woke them up and shook their homes. One caller said a picture fell off a wall. Nixa police say echoes from the fireworks after the Springfield Cardinals baseball game could have caused the rumbling.