CBS has dismissed the general managers at two of its owned-and-operated local broadcast stations.

As of this week, Derek Dalton of Chicago station WBBM-TV (Channel 2) and Jay Howell of duopoly KCBS (Channel 2) and KCAL-TV (Channel 9) in Los Angeles will no longer be employed by the company.

The firings come amid a sweeping investigation into the broadcaster’s corporate culture at all levels, triggered by allegations of misconduct and mismanagement at some local CBS stations in other parts of the country.

Executives offered no information as to why Dalton and Howell were being dismissed. In an e-mail message sent to station employees, CBS entertainment executive George Cheeks said the investigation proved to be a “difficult period for everyone in the group.”

“The investigation cited painful revelations about experiences that we cannot tolerate today or in the future,” Cheeks wrote.

The company has started to look for replacements for both men at each broadcast outlet.

The CBS broadcast network and its local stations group are divisions of ViacomCBS.