It's one of those deals where they won't take a notice. They want you gone as soon as you tell them you are going to quit.
Some jobs are like that. They don't want the soon-to-be-ex-employee to have a week or two in which (s)he could sabotage what they work with. In IT, a soon-to-be-ex-employee has their access to whatever they worked on cancelled as close to immediately as practically possible.
My boss actually smiled at me and shook my hand when I told him I was quitting. That was a strange reaction.
Is this the truck driver DU member who was complaining recently that his hours had mysteriously been cut? If so, the boss was probably thinking,
"It worked! We didn't have to fire him, and we didn't have to deal with his unemployment insurance claim! Good riddance, dude, and thanks for doing what we wanted you to do!" Maybe seasoned with a few expletives.