In 1980, the seismograph at Texas Tech University recorded and "event". Calls to the USGS could not confirm the event. One week later at about the same time, another event was record that was more severe than the first. Same day and time for the third week a lesser event occurred.
It turns out that there was a new (FNG) Dr Pepper delivery person making rounds for the soft drink machines on campus and in order to out of one location, he would bump the rear of his truck in the building hosting the seismograph.
Barriers are now in place.