Just offshore of the towering national monuments of Washington, a tall crane now hovers over the Potomac River. It casts a large shadow over the effort to understand what caused the collision of a passenger jet and a military helicopter last Wednesday as a new phase of the recovery starts.

Wind gusts and tidal conditions could slow recovery operations today after the midair collision of a passenger plane and helicopter last week.

The National Transportation Safety Board has recovered two importance pieces from the wreckage of the medevac plane that crashed in Philadelphia last week.

Investigators found a new lead amid their probe into the cause of the deadliest plane crash in nearly 25 years in Washington DC.