An asteroid impact would have left a large crater, perhaps across, none of which was found. Alternatively, a bolide, or air burst, caused by a stony asteroid of up to some tens of meters in diameter, would not have reached the surface but likely would have exploded in the atmosphere, creating a large shock wave but not an impact crater. This option, the possibility of which was driven home by the widely observed February 2013 Russian meteor event, would have led to measurements and observations that are entirely consistent with data and eyewitness reports, far more so than a seismic disturbance, which would be difficult to reconcile with fireball sightings.