NEW YORK (MainStreet) — Blackberry. Nokia. Bear Stearns. Three poster boys for businesses that, once high flyers, imploded - and often it is the employees who pay the price as they are belched out of a dying corporate carcass into long unemployment lines.

The question is plain: are you working in a company that is heading to the graveyard?

Big companies spectacularly die; little companies by the tens of thousands fade away. But know that all of them displayed telltale signs of impending failure. Savvy workers often see those signs early and they bail them out.

Name that the first sign a company is heading into a deadend: When the best and brightest workers, the ones plainly tabbed for fast-track promotion, abruptly turn in their resignations and head off to new jobs elsewhere - well, it's time to polish that LinkedIn profile. There just is no louder warning bell.

But there are plenty of other signals workers need to stay alert to if they don't want to drown on a sinking ship.

* The pay raises have stopped: Angie Segal, from ActionCOACH, said that a sure sign of a dying company is when "it has been more than a year since the last raises were given." Generally a company stops giving raises at the first sign of trouble, and if it isn't able to re-institute those raises, nothing has changed to turn it around. Note: make sure this isn't just your problem. It's when everybody's pay is frozen that the company is on life support. If only your pay is frozen, it's definitely time to leave but for wholly different reasons.

* Stagnation rules: David Lewis, CEO of HR consulting firm OperationsInc, said you know a company is in trouble when "your boss has been in that role for X number of years, as has their boss - and so on - and you do not see any place for them to move upward...meaning you are not going anywhere." This means the company hasn't grown in a long time, and that is a warning bell to head to the exits.

* Shut doors darken the hallways and hushed voices whisper about the troubles they see:

According to executive coach Kathi Elster, a dead-on sign of an expiring business is when "there are many closed door meetings where people come out looking devastated." If you are seeing those deer-in-a-headlight looks on the managers, know the clock is clicking louder.

* Your benefits have been cut: Bosses may blame Obamacare, they may blame competitive pressures, they may blame the full moon. It doesn't matter what they say. Noted Michael Provitera, author of Mastering Self-Motivation, when a company takes an ax to its benefits package, you know it's all over. Good companies use rich benefits to become an employer of choice (think Google or Facebook). Dying companies plain don't care anymore about who punches in. Be especially wary of fancy mathematics designed to camouflage a benefits cut. If it quacks like a duck, you know what it is.

* You've just been merged or acquired: Bosses always say "there will be no impact on our jobs." They lie. Said Dana Manciagli, an author and global career expert: "No matter what the leadership says, when there is a merger or acquisition, there will be an elimination of redundant heads. It may not be immediate, but it's coming."

* Blame the customer: Customers have voices in the Internet era but a common trait among companies heading to extinction is to shrug off their negative feedback. When your bosses get defensive - or they claim cutthroat competitors posted "fake" reviews - and they always go into this turtle-in-the-shell denial, know that you will not have a job for much longer.

*Your mother calls and asks if you still have your job: According to Vicky Oliver, author of Bad Bosses, Crazy Coworkers & Other Office Idiots, ion an era of the Internet and social media, bad news travels fast and secrets are hard to keep. "If your immediate family members are worried, chances are there's a good reason why," said Oliver. "Try to figure out how your skills will mesh better in a job that's not a dead end."

--Written by Robert McGarvey for MainStreet