What in-flight turbulence is and when it becomes dangerous for passengers and crews

A Delta Air Lines flight from Salt Lake City to Amsterdam has been hit by severe turbulence, sending 25 people to hospitals and forcing a diversion to Minnesota. The Wednesday evening flight highlights the dangers of traveling through unstable air. Experts note that the number of turbulence-related injuries has increased, possibly due to climate change affecting flying conditions. Turbulence-related fatalities are rare. Experts advise travelers to stay vigilant and wear seat belts. Airlines have also tried to improve safety.