Air traffic has become increasingly complex and congested in the Baltimore region and around other national flight hubs, raising questions about ways to boost safety a day after the deadly midair collision at Ronald Reagan National Airport.

Are plane crashes becoming more common? Washington DC mid-air collision questions answered - Lessons will be learnt from this tragedy and will contribute to future air safety

A plane carrying 60 passengers and four crew members crashed into the Potomac River in the US shortly after 9pm local time at the Ronald Reagan National Airport