Earthquake in South Carolina and North Carolina

Yesterday evening, I was in the kitchen when suddenly a bookcase in the corner toppled over and dumped all the books out. I told my oldest, "I wonder what caused it to fall since its been there for 5 months now." Today I get the news email letter and see that there was a small earthquake at the same time so I am thinking that even though it was quite a ways off that there were possible small tremors that shook the apt complex and caused this to happen. Otherwise I can't see why this bookcase would suddenly fall over when it hasn't been touched in months even.

2.9 Magnitude Earthquake Rattles SC, NC