By NBC’s own admission, Matt Lauer’s behavior was “appalling.”

The swift fall last week of the superstar co-anchor of “Today” left NBC News once again reeling from scandal and facing intense outside scrutiny of the management of the division. Lauer was fired Nov. 28 after more than 20 years with NBC News and “Today.”

NBC had no choice but to act after a current employee came forward to management with disturbing allegations of inappropriate sexual conduct by Lauer. NBC was also under extreme pressure from a two-month Variety investigation into sexual harassment allegations against Lauer that was published on Nov. 29.

Four days after Lauer’s ouster, NBC News chairman Andrew Lack announced the network would undertake a “thorough and timely review” of company policies and practices. The move comes amid simmering outrage among staffers at NBC News and other divisions that Lauer’s behavior went unchecked for so long. Although NBC News said there had been no prior complaints about Lauer, there is widespread disbelief within the division that senior management had no inkling of his troublesome tendencies and that he made many women on staff uncomfortable.

“Many of you have asked what we are doing to learn as much as we can about the circumstances around Matt Lauer’s appalling behavior, why this was able to happen, and why it wasn’t reported sooner,” Lack said in announcing the review.

Lack and NBC News president Noah Oppenheim made the rounds with staffers in the days following Lauer’s ouster, promising to impose a zero-tolerance policy for harassment.

But eyebrows were raised by the fact that the investigation would be handled by NBC News and NBCUniversal human resources executives rather than an outside firm. Amid the shock that Lauer’s behavior could have gone on for years unchecked, there was skepticism that NBCU insiders would take as hard a line with management on the question of whether there was a concerted effort to protect the star anchor because of his importance to the profitable “Today” franchise.

NBC News declined to comment. But a source close to the situation emphasized that a primary goal is to find ways to empower employees to speak out when problems first arise, and that was viewed as a process best handled by internal HR veterans.

The allegations against Lauer adhere to the now-familiar pattern of a powerful figure leveraging his immense clout in the company to engage in unconscionable sexually charged behavior that deeply traumatized his victims. Lauer’s lightning-speed demise at “Today” makes him the latest addition to the list of disgraced media and entertainment figures who faced a reckoning in the public square as victims have been emboldened to share their stories. The complaint that got Lauer fired was a relationship with a co-worker that began while the two were in Sochi, Russia, covering the 2014 Winter Olympics. NBC was forced to acknowledge that it also had good reason to believe that such behavior was not an isolated incident for Lauer.

Although Lauer’s reputation was an open secret among many “Today” staffers, his ouster left the news division in a state of shock. “It doesn’t get bigger or better than Matt around here,” said one NBC staffer. Insiders said nothing encapsulated the mood like the shakiness in “Today” co-anchor Savannah Guthrie’s voice as she announced his firing to viewers at the top of the Nov. 29 edition of the show.

One female NBC News staffer admitted to having mixed emotions about the situation because of the long tenure that many have had in working with Lauer. The source described the anchor as outwardly projecting an image as a “consummate gentleman” who was generally gracious to staffers and fun to be around. But sources suggested that his temperament and attitude had changed significantly in the past few years, amid what co-workers chalked up to the strains of the job and tensions in his marriage.

Lauer’s departure leaves a larger void in that he was very active in steering the daily direction of the 7-9 a.m. edition of “Today.” He was a key player in working with executive producer Don Nash and others on selecting stories, assigning correspondents and developing segments for the broadcast.

The sway that Lauer exerted over “Today” was another big reason why those who were targeted were fearful of coming forward. In one instance, as Variety reported, he gave a colleague a sex toy as a present with a note about how he wanted to use it with her. The experience left her mortified. Another instance reported to Variety involved Lauer exposing himself to a female employee in his office. When she refused to engage in a sexual act, he reprimanded her, according to the source.

The revelations in Variety about Lauer’s behavior precipitated anxiety throughout NBCUniversal’s 30 Rockefeller Center headquarters. Undoubtedly, the tarnish to the company image has caused the same at the highest levels of parent company Comcast.

The outpouring of sexual harassment stories across the industry during the past two months had already spurred NBCUniversal to develop plans for expanded training for managers and more mechanisms for employees to bring forth complaints. Until Lauer’s downfall, sources said those efforts were seen as a prudent proactive measure in the face of a larger cultural problem. Now, NBCUniversal is very much on the defensive. “It’s harder when you have to clean up your own mess,” a longtime NBCU executive said.