How did newly deposed CBS Early Show producer Shelley Ross pull off one of the biggest career self-sabotages in television history? By burning every single bridge she could, both inside the network and out.

Ross, the prototypical mean girl, began alienating co-workers almost as soon as she started, sources tell Radar. But that's not uncommon in the industry; others have done the same and survived. Ross took it to the next level. Some of the more outrageous elements that lead to her downfall:

• The extensive use of recreations and reenactments made most of the staff uncomfortable. Ross' attempts to make stories seem juicier by adding dramatic music was similarly troubling. There are also accusations that Ross would pre-produce answers to questions in segments. A recent piece on Second Life in which its ostensible subject was never shown infuriated anchor Harry Smith.

• Ross went way over budget, seemingly at whim. Particularly telling: Ross allegedly spent a ton of money to make weatherman/feature reporter Dave Price miserable, sending him all over the country on terrible assignments.

• Her staff was demoralized. Twenty-one people left during her tenure. In fact, we're told that so many people wanted to leave that they couldn't even quit, because they couldn't get in to tell Ross they wanted to go and she refused to answer her e-mails.

• Her slash-and-burn booking policy damaged the show's reputation and outside relationships. For example, back in January the show was supposed to feature a musical performance in honor of Phantom of the Opera's 20th anniversary, a performance CBS solicited. Ross canceled it at the last minute without explanation.

• Her accomplices only made things worse. Laurye Blackford, a close Ross associate who had worked with her at Good Morning America, was brought in "temporarily" as Shelley's number two, but never left. Blackford has been formally reprimanded for being abusive to the staff. No word on whether she'll remain now that Ross is out.

Perhaps most damaging, however, was Ross' refusal to do any CBS-friendly promotion. This was not some play for editorial freedom, however: sources say it came from Ross' hatred of CBS president Les Moonves. (The feeling is apparently mutual.) Not only did this alienate the powers on the West Coast, it angered Early Show co-anchor Julie Chen. Ross' decision not to promote Big Brother didn't sit well with Chen, either—in addition to hosting the show she also happens to be married to Moonves. ("Every night Les goes to bed with a headache," said a source.)

All in all, a picture of a frighteningly dysfunctional workplace. But in the end CBS had the last laugh: They had Ross come in to work on Monday to try and smooth things over with her staff and tell them that she was staying. Then CBS News president Sean McManus [RELATED: How does this man still have a job?] called her down to his office and fired her.

Reached via phone, a CBS News spokesperson declined to go beyond an earlier statement.