I was awake when it struck, and I received this alert about 3 seconds before the shockwave hit my location:
My phone was isolated from the shockwave due to it being in my hands at the time, for what it's worth.
JeffP
The VP Engineering for Android posted a visualization of the 4.5 earthquake in
Southern California from data collected by Android phones.
https://twitter.com/davey_burke/status/1307395583338885120
USGS ShakeAlert is transmitted via WEA to Android, iPhone and other cellular
devices; and shared directly with some public-private partners. Most
smart devices (Android, iPhone) collect diagnostic logs and report back to
their developers, but generally emergency responders never see data from
diagnostic reports.
Developers don't include emergency alerts in other "smart" devices like
SmartTVs, SmartSpeakers, etc.