Not what I said:

GPS locator, ambient sound etc sensors kicked in, an alarm/text message could have gone to her parents cells indicating her routine was disrupted, folks could have called 911 for help

Chelsey never had a chance to grab her phone and press a panic button or call 911.

http://www.facebook.com/pages/Rename-RB-Community-Park-Chelsea-King-Memorial-Park/338902172098

At the SHM, this was used as an example only regarding a safety/get help feature of the tech.