My experiences of layoffs are:
1. A job in a huge software house. The company didn't hit the 12% profit margin it had promised it's shareholders, making a "measly" 10%. People knew when they were being laid off when the person going round with some fold up boxes dropped one at your feet and said, "pack your stuff". I wasn't laid off at that time but plenty of people I worked with were.
2. A minimum wage job when I was 19 years old. The owner calls us in and sacks a bunch of us in one go, with a big fat "sorry". I asked what the severance package was, since no-one else wanted to ask. He said, "erm, er....", and when it became clear there wasn't one because he hadn't enough empathy to even consider the proposition I said, "you can at least give us some money to go to the pub." He laughed, others nervously laughed. I said, "12 of us multiplied by a tenner each is £120". I eventually got £60 off the miserable excuse for a cunt who had his new Aston Martin parked on the carpark directly outside the window. (Yes I made sure everyone who got laid off got an equal share of that £60 at the pub).