MEXICO CITY -- As we reported earlier this month, Mexico City's government unveiled, with much fanfare, a free app for residents' BlackBerrys that would send out an alert when a major earthquake was approaching. It would give the user up to 50 seconds' warning, time to clear a building or run into the street. Crucial seconds, Mayor Marcelo Ebrard told us.
Well. There's a catch. The alert only activates when the quake's epicenter is in the southern states of Guerrero or Oaxaca. So Wednesday's 6.5 in Michoacan didn't trigger the alarm. Our BlackBerrys (where we had eagerly uploaded the app last week) remained silent as our offices and homes began to shake.
This missing detail put Ebrard and members of his government on the defensive. They took to their Twitter accounts to explain that the system is gradually being expanded so that alerts will eventually come from additional states.
Ebrard said he decided to launch the app even though quakes in only two states would send out warnings because partial coverage was better than waiting for the entire system to be up and running (link in Spanish).
The Michoacan quake, downgraded from an initial reading of 7.0, was the second big shaker in three weeks in Mexico and caused no major damage; a 7.4 quake March 20 that was indeed centered on the Guerrero-Oaxaca border cracked hundreds of homes there and killed two people. Early Thursday, a 6.9 temblor hit off the coast of Baja California.
-- Tracy Wilkinson
Photo: A man walks out of a damaged home in southern Guerrero state, site of a powerful March 20 earthquake. Credit: Pedro Pardo / AFP / Getty Images