VIDEO: Shopping malls in the United States are losing out to online sellers. Find out what developers are doing to repurpose malls to fit a changing American commercial landscape.

ON THIS DAY IN AMERICAN HISTORY On March 26, 1953, Dr. Jonas Salk announces he has successfully tested a vaccine against the polio virus. The disease, which mainly affected children, reached epidemic levels in 1952, with around 58,000 new cases in the United States. More than 3,000 died from the paralysis-causing disease. For two years, the vaccine underwent clinical trials, and in 1955, a massive inoculation campaign began.

As the largest economy in the world, the U.S. produced $20.5 trillion worth of goods and services in 2018. That’s impressive when you consider that the total for the entire world was about $80 trillion in 2017. In fact, every U.S. state has an economy that makes it as economically powerful as any nation.

VIDEO: The Wayfarers Chapel on the California coast is often called the “glass church.” It’s a hidden gem tucked away among large redwood trees. VOA gives us a look at the building, which is listed in the National Register of Historic Places.

The Campaign to Stop Killer Robots warns chances of achieving a U.N. treaty banning the development, production and use of fully autonomous lethal weapons, also known as killer robots, are looking increasingly remote.

VIDEO: With local elections in Turkey set for this coming Sunday, the vote is seen as a crucial test for the pro-Kurdish People’s Democratic Party in the country’s predominantly Kurdish southeast. Most of the HDP’s mayors and parliamentary deputies are in jail, accused of supporting a Kurdish insurgency. Still, as VOA reports from Diyarbakir, the largest city in Turkey’s Kurdish region, HDP candidates are running for office.