Translation:They got off
The word "alight" is used in kenyan english although both alight and disembark sound quite oldfashioned in modern English.
I used to get trains fairly often. Always heard the friendly recorded voice saying "please mind the gap as you alight from the train".
Alight should be correct. I checked with my Kiswahili teacher (I'm Kenyan btw) ans she said its ok
Yeah, few people in countries I've been to would use these naturally, but voice recordings on public transport often use these words.
Disembark does mean the same but is more commonly used for boats and airplanes. As Graham says, it's not eally everyday speech but both disembark and alight are used sometimes in official communications.