Companies have struggled for years to find the right euphemism - downsizing, right-sizing, off-shoring - but it all comes down to the same thing: people are getting fired. Fortunately (or unfortunately) companies have had a lot of practice at this and many manage it quite well. At Scient in 2000 we excelled at two things: hiring boatloads of people when times were good, and getting rid of them when times got tough. I'd say that firing people became one of our core competencies.
Usually a layoff or bankruptcy isn't a complete surprise. A round of funding for a startup doesn't come through, or sales aren't growing or are declining for a long period of time, or a product flops. It's really expensive to hire good people, so layoffs are typically a last-resort, especially considering the effect on morale.
Let's look at some of the warning signs.