Turns out, the earthquake was in Guatemala but was so strong it was felt all the way here in Mexico City. DF actually does have quite a few earthquakes, mostly because it is a city built on an old lakebed and is considered one of the most active trenches in the world; recording more than 90 earthquakes a year. However, most are very mild and people continue what they are doing. After the destruction and death from the famous earthquake that hit in 1985, all the buildings are now properly designed to handle them. Phew! You learn something new everyday.
*Donde te agarro el temblor? = Where were you during the earthquake (more or less)