The Los Angeles Police Department unveiled a new communication service Wednesday that can notify the public immediately about everything from evacuations to Amber Alerts via text message or e-mail.

Nixle is the first professional-grade mass communications system allowing the LAPD and other agencies to communicate directly with a geographically specific portion of the community, Police Chief Charlie Beck said.

Beck explained it's similar to "a professional-grade Twitter," and he urged Angelenos to sign up for the service.

During mudslides, LAPD can use Nixle to alert registered residents when it is time for them to evacuate and where they can find shelter.

"It is a secure way for the Police Department to reach out to people in times of crisis," Beck said. "It's very similar but more detailed than reverse 911."

Nixle co-founder and CEO Craig Mitnick said if the system had been available during the Sept. 11, 2001, terrorist attacks, "it would have been a far different outcome, trust me."

Authorities said Nixle can also notify registered users about crime-related traffic jams; crime patterns in specific business communities; and even missing dogs in their neighborhoods, if they sign up for such information.

In case of an Amber Alert, the Police Department can use Nixle to disseminate photos of the missing child and the suspected kidnapper, as well as provide a link between volunteer searchers and the LAPD command post in charge of the investigation.

Beck said the information that goes out through Nixle is secured, so registered users can trust it.