As more and more people cut the landline in favor of a cell-phone, concerns are growing over what's commonly known as \"reverse 9-1-1\".

The feature allows emergency management to reach groups of homes during chemical spills, local emergencies, or active shooter situations.

This was the case on April 7th, when a man started firing his gun outside his home in New Berlin. That man later fired at police, and eventually turned the gun on himself.

     \"We needed to alert the entire neighborhood about what was happening,\" says Captain Mike Glider. \"People even being in their own homes were not safe that night.\"

Waukesha County Communications sent out an Emergency Telephone Notification, telling people to shelter in place and lock their doors.

That notification is an automated message, sent to landline phones that are listed publicly. 

     \"With the weapons that he was firing, the rifle that he was firing had a range of a mile, which would have covered this whole subdivision,\" says Glider.

That call went to 89 homes. Glider says It reached a total of 2.

     \"If you have a wireless phone, or a non-published phone number, you will not get that notification unless you sign up individually for those alerts,\" says Gary Bell. 

Bell is the Director of Emergency Preparedness for Waukesha County, and says the technology is reaching fewer and fewer people as cell phones become the prominent choice for Americans.

He's asking people in Waukesha County to sign up for the alerts. It will not put you on any other call lists. 

     \"We want you to know as soon as possible what the dangers are, and what we need help with,\" says Glider. \"This is one of the times where it could have really been used the most.\" 

Waukesha County residents can sign up to receive the alerts here. 

Milwaukee County residents can sign up here.