Inside Ukraine's 'Kill Zone' where soldiers face swarming killer drones

Описание: The 'Kill Zone' runs along the 750-mile front between Ukraine and Russia and is about 20 miles wide. It's likely one of the deadliest places on earth right now, as swarms of new high-tech drones act as killing machines. NBC News' Richard Engel talks to Ukrainian soldiers fighting to survive in this new era of warfare.