Armed soldiers guarded abandoned buildings at risk of collapse. Some 52 buildings collapsed in Mexico City alone and more in the surrounding states.
The extensive damage to many buildings, some of them relatively new, raised questions over construction standards which were supposed to have improved after a devastating 1985 quake.
The quake came on the anniversary of a 1985 earthquake that killed thousands and still resonates in Mexico. Annual Sept. 19 earthquake drills were being held a few hours before the nation got rocked once again.
Mexico was also recovering from another powerful quake less than two weeks ago that killed nearly 100 people in the south of the country.