The death of South African leader Nelson Mandela Thursday sent news networks scrambling to cover the legacy of one of the 20th century’s most influential and revered political activists and humanitarians.

News of Mandela’s death at age 95 broke late Thursday afternoon ET, which meant a race against time for the Big Three nets to cover the story on their evening newscasts.

As of Thursday evening, none of the major broadcast nets were expected to preempt regularly scheduled primetime programming. NBC has its long-awaited “The Sound of Music Live” telecast set to roll tonight. The Peacock said it would offer expanded news coverage in the evening but had no plans to bump the live musical telecast.

CBS also said it had no immediate preemption plans for Thursday but might offer additional primetime coverage on Friday or Saturday.

The news cablers went into wall-to-wall coverage mode. CNN bumped the planned premiere of its docu “An Unreal Dream: The Michael Morton Story” for a primetime block anchored by Anderson Cooper. CNN also has  correspondent Robyn Curnow on the ground in Johannesburg.

Shepard Smith anchored Fox News’ coverage, with Bret Baier scheduled to take over at 6 p.m. ET. FNC’s coverage of Mandela’s death was expected to continue during the regularly scheduled programming throughout primetime.

Al Jazeera America brought in Ali Velshi, John Siegenthaler and Tony Harris to anchor coverage. The story will give the fledgling U.S. news net an opportunity to demonstrate the depth of its parent org’s international bureaus in showcasing global reaction to Mandela’s passing.