While it's a little later than expected, the free SMS emergency notification system has now gone live. Wireless Emergency Alert (WEA) messages will be delivered to cell towers in affected areas, which will then broadcast them to all compatible devices in their range. While the system is looking to cover over 97 percent of the country, it's being gradually rolled out across carriers. Sprint and Verizon are both apparently ready for action and while we haven't heard about the status of T-Mobile or AT&T, the National Weather Service has stated that hundreds of smaller carriers haven't yet enabled the broadcasts. However, not all phones -- especially the more elderly bricks still in circulation -- will work with the system. To check whether your weighty cellular still passes muster, hit up the compatible device list at the CTIA link below.