Mexico is finally getting a single, nationwide emergency number like the U.S. has, and the number is 911.

In Mexico's previous system, people often reported police emergencies to one number, and medical or fire emergencies to another.

And the public has long distrusted emergency numbers because authorities frequently fail to come when called. In northern Mexico, the army launched a crime-report number called "We do show up."

Trust hasn't been helped by reports that some dispatchers tipped criminals off to call-in complaints.

The government apparently seeks to imitate the perceived reliability of the U.S. number.

The gradual change was completed Monday, but not much public outreach was done.

The newspaper Reforma reported in a headline "911 starts up, and nobody knows it!"