LONDON (AP) — The bungling of reports that powerful Britons sexually abused children has thrown one of the largest and most respected broadcasters in the world into a deep crisis.

It is hard to overstate the importance of the BBC in British society; its influence stretches throughout the former British empire and beyond. Over the years, the BBC has been behind almost all of the U.K.'s broadcast milestones, serving as a voice for the British nation. Its airwaves have carried the clanging of Big Ben's bells, wartime messages from Winston Churchill, and the music of the Beatles — exporting British culture to a global audience.

The head of the BBC's governing body vowed Sunday to overhaul the broadcaster. That could mean many things for the sprawling organization that has long emphasized its obligations to the public. To know what it would take, it is important to know what the BBC is and the scale of the crisis it faces.

WHAT HAPPENED:

Last month, the BBC drew fire after it emerged its "Newsnight" program had shelved an investigation into child sexual abuse allegations against Jimmy Savile, the broadcaster's renowned TV host who died last year.

Police say that since their investigation started they have received complaints from some 300 victims of the platinum-haired, tracksuit-wearing Savile and associates — and that some of the abuse may have occurred on BBC premises. Questions soon arose over whether shelving the "Newsnight" piece was part of a cover-up or if BBC managers had heard of but ignored claims of abuse by Savile while he was hosting such shows as "Top of the Pops."

Amid public outrage, BBC director general George Entwistle announced internal inquiries into why the "Newsnight" investigation was canned as well as the BBC's "culture and practices" during the years Savile worked there.

But then, "Newsnight" wrongly implicated a British politician in a sex-abuse claims program that aired Nov. 2.