The ground shaking is becoming an all too common wake-up call in parts of the ArkLaTex. Just hours after a 4.1 magnitude earthquake shook East Texas, many are now asking why this keep happening and what if the rumbling gets rougher? From shock and concern to the quick realization that, once again, the ground is rumbling in Shelby County. That's the reaction from those who felt Thursday night's earthquake in Timpson. The trembles reported as far east as Bossier City. Fortunately, this one left just a small mark behind. But what if East Texas were to experience an earthquake with a magnitude greater than 4.1, that could mean trouble. Emergency Management Coordinator, Larry Burns says, "If it gets over a 5.0, then we could have some catastrophic damage. As the dust settles, the focus now looks to the cause of the shakes. Everyone has his own theory. According to research ongoing at Stephen F. Austin University and University of Texas, Burns tells us they've got some ideas about the cause but, for now, they're not publishing any of those findings.