April 17, 2019 - PBS NewsHour full episode

The White House says Americans will now be able to sue businesses operating on land confiscated by the Castro regime. Previous administrations declined to enforce the related Helms-Burton Law. Canada and the EU, which have private-sector interests on Cuban land, decried the move. Nick Schifrin talks to National Security Advisor John Bolton about that, plus U.S. policy on Venezuela and North Korea.

It has been nearly 20 years since the first mass school shooting in the U.S. -- the shocking tragedy at Columbine High School in Littleton, Colorado, on April 20, 1999. As a “credible” threat closed Columbine and hundreds of other Denver schools Wednesday, John Ferrugia of Rocky Mountain PBS shares part of an upcoming documentary featuring survivors of the massacre in their own words.

Steve Martin and Martin Short have been nearly inseparable since meeting more than 30 years ago on the set of “Three Amigos.” The two legendary Hollywood comedians sat down with Steve Goldbloom to discuss their latest touring special, “Now You See Them, Soon You Won’t” and their brief but spectacular take on their “fabulously popular and undeserved success.”

How are those closest to the Columbine school shooting observing its 20th anniversary? Coni Sanders’ father, David, was a teacher and coach at Columbine and the only adult killed -- but not before he warned hundreds of students to safety. David Cullen is a journalist who was at the scene. Lisa Desjardins talks to both of them about their memories of horror and how life has moved forward since.

Antarctica was the last of the seven continents to be discovered, and it wasn’t until the late 1950s that commercial tourism began there. But now, Antarctica has become a popular travel destination, amid growing concerns about the effect that increasing numbers of people could have on its pristine environment. William Brangham reports from Antarctica.