FARGO, N.D. -

Some people in the metro received the Amber Alert on their phones on Saturday, some did not.

Fargo is right on the edge of the alert that was issued for the 5-year-old girl from Watkins, Minn. who was abducted and later found dead.

If you're wondering why you didn't get the Amber Alert on your phone on Saturday, it's not a mistake made by the emergency alert system.

Your phone may have picked up a signal from a farther tower, which in the end results in more people looking out.

Amber Alerts on your phone.

It's a sudden beep, that can catch you off guard.

And that's what many people in both Fargo and Moorhead heard on Saturday after a Alayna Ertl was abducted about three hours away.

"I checked my phone and I was very concerned," says Christina Sanchez, Fargo.

Others did not.

"It didn't pop up on my phone, I had to look on my Facebook," says Josh Olson.

But alerts weren't short handed.

People in Fargo's phones picked up alerts that came from farther towers.

"It's very similar to your FM radio in your car, as you drive into an area you may have gotten the alert or if your phone was bouncing off that particular tower even if you may have been out side of the state you were still within that geo-fence that was set up," explains Mike Murphy, from the National Center for Missing & Exploited Children.

If you have an iPhone you can check if your emergency alerts are on by opening your setting and scrolling down to the bottom

Alerts go for out for 24 hours, and will go off when you enter that area.

"The purpose of that is to get the right message to the right people in a timely manner," Murphy says.

As a mother to a 2-year-old, Christina hopes people are willing to keep the alerts on.

"I don't know what the excuse would be for people who didn't want that amber alert. I mean you should always be updated on what's currently going on," Sanchez says.

Different phones work at different speeds which may affect the time you get an alert.

But officials say those who are in the geo-mapped counties did get the alert they needed to see.