Strange siren in San Francisco

[HudsonRiverSirens]

I was browsing some videos to see if I could find a video of San Francisco's system during an actual warning. I did, but it provides some mysteries: https://www.youtube.com/watch?v=5SzPjlFoEB0
What is the tone being played, and why is it not the STL-10? What is with the weird pitch differences? If anyone could answer these it would be great. Also please notify me if any information is provided in the comments, as I cannot see them at this time.

[uncommonsense]

1) STL-10 tone is only used for tests

2 This is very obviously a dying SiraTone (you can hear others working fine in the background). The audio is overdubbed; note it plays right through the driving without Doppler effect and plays right through the scene cuts without interruption or change. There’s a lot of dying STs like this in Hawaii and that’s where the audio is from.