Nine staff at Morris Plastics were made redundant after the firm announced it was leaving its premises in Sedburgh Road, Halifax.
Days earlier, according to a source, workers had been warned they could be facing difficulties.
The Halifax employees who assembled products at the industrial estate were offered the choice to move to the plastic company's manufacturing plant in Eccles, but refused.
Morris Plastics moved to the Halifax site a few months ago from Watson Mill Lane, Sowerby Bridge.
Terry Thompson, landlord of the industrial estate at Sedburgh Road, said: "They left just like that. It is a real shame for the people who worked there. I feel very sorry for them.
"The company has left a lot of stuff behind but I've blocked the doors off with two big rocks. I'm furious with how they acted."
A worker at a neighbouring business said: "I knew one of the girls who worked there and she came in the day it happened and just said 'See you later.' She was really upset. To hear news like that before Christmas is awful."
John Harlow, a solicitor at Morris Plastic's administrators, said: "The company has an Eccles plant which is still trading and the staff were given the opportunity to move there but none took it up.
"We are working hard to salvage something if we can and I have had some interest in the business. Morris Plastics is insolvent and needs assistance."
The Courier has been unable to contact Morris Plastics for a comment.
joe.shute@halifaxcourier.co.uk