Anna Staropoli
The Kentucky Derby is the biggest horse race in America, and preparing for it takes millions of dollars and thousands of people. We went to Churchill Downs days before the big race to see what it takes to train the winning horse and prepare the century-old track for 400,000 fans.
Courtesy of Teddy Almond & Drew Angerer/Getty Images
Viktor Kovalchuk/Global Images Ukraine via Getty Images

Three hackers in Poland were hired to fix the software of a broken train, and they were successful, but now the train company, Newag, is threatening to sue them, according to Polish outlet Rynek Kolejowy.
Stefano Rellandini/AFP/Getty Images
Biden is pouring $16 billion into making Amtrak trains faster, easier to get to, and more accessible
Drew Angerer/Getty Images
Arantza Pena Popo
Tori Ferenc for Insider
North Korean dictator Kim Jong Un travels abroad in a bulletproof train that's been used for generations. Archival footage and an expert reveal the root of the family's paranoia and what goes on inside the "Moving Fortress."