I think they were all it about the same time as L.A. They were attacks by Terrorist, Foreign Country, or Religious Freaks. Wether they got wiped out (accidentally or otherwise) is still up in the air.
Proof:

DVR
1. It mentions that similar "riots" were happening in majors cities around the world.
2. Everything recorded even an hour latter was nothing but static. (unless everyone who lived in the tower before that had a DVR only had cable; I doubt people with DVR and satellite would have their reception knocked out an hour after news coverage.)

Kalani
1. "Did you think they (zombies) swam to Hawaii?"
2. He mentions that the ones there seemed a bit meaner. With Hawaii being small islands the Adv. Flesh Biters would seem more common.
3. The other tower had taken "strange devices" from ground zero.
4. Scavengers got sick when they got close to ground zero.