Well mine looked worst than that one year, but it did come back. I think my problem was underwatering. My irrigation actually stopped working while away. After watering again, it bounced back so I would say there is hope.

I spoke to three nursery people. Two thought it might be grubs. One (supposedly more experienced) said it wasn't getting enough water - even though the other two trunks looked ok. Unfortunately, my dilemma was somewhat "solved" today when my yard guys took it upon themselves to cut out the dead trunk. I was not happy at all, but the bottom of the trunk does look completely dead. I will continue to water more and add some palm fertilizer to ensure I don't lose the final two trunks.

It could be a palm tree disease of some kind. It seems to be starting at one point and spreading out.