There was a M4.9 event in Alabama on April 29, 2003. The event time was 08:59GMT, or 05:59 EDT. This event created a surge of traffic on the Earthquake Hazards Program web servers.
Here is the traffic on the Earthquake Hazards Program web site, as reported by Akamai. The peak is about 74 hits/sec. The peak occurred at about 30 minutes after the event. As in the event in Indiana last summer, this event was located in an area where people are not as aware of earthquakes as we in California are. California events always generate peak traffic at 10 minutes after the event. Note that the traffic tailed off a bit before a steady swell began at about 08:00 EDT which continued through the day. Traffic averaged around 60-70 hits/sec all day.
As of this writing there were no reported problems with web service after this event.
The National Earthquake Information Center got a small surge right after the event, and a large surge of traffic starting at about 13:10 GMT, which corresponds to about when the special report page went up for this event. The highest rate during this time was about 250 hits/sec.
Here is the traffic summary for the Pasadena web site as reported by Akamai. The hit rate was fairly modest at around 40-50 per second, but it was steady throughout the day. Most of this traffic is due to people either viewing the map or submitting questionnaires for the Community Internet Intensity Map.