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 was affected by serious turbulence, sending 25 people in hospitals and forcing a diversion to Minnesota. The Wednesday evening flight highlights the dangers of traveling in the unstable air. Experts note that the number of injuries related to turbulence has increased, perhaps due to climate change affecting flight conditions. Deaths related to turbulence are rare. Experts advise travelers to stay vigilant and wear security belts. Airlines have also tried to improve security.