In a company-wide memo released publicly, Lack said those are among the questions NBC employees are asking in the wake of the "Today" host's firing for what Lack labeled "appalling behavior."
A team of NBC Universal legal and human resources leaders have started a "thorough and timely review" of what occurred and how the company can foster greater transparency and mutual respect, Lack said in the memo.
"At the conclusion of the review we will share what we've learned, no matter how painful, and act on it," he said.
His memo didn't address if the report will be made public.
NBC News publicists didn't immediately respond to a request for comment.
Reiterating comments from a memo he sent Wednesday, Lack said the top priority is to create a safe workplace environment and that unacceptable actions are "met with consequences, no matter who the offender."
NBC's announcement Tuesday that Lauer was being fired for "inappropriate sexual behavior"meant that the network was cutting loose the popular, long-established star of its highly lucrative morning show.
How much Lauer's status may have protected him from allegations is among the questions raised by observers. NBC has said current executives didn't receive any complaints before the one Monday that triggered Lauer's immediate dismissal the next day.
- Associated Press