A jet carrying 60 passengers and four crew members collided Wednesday with an Army helicopter while landing at Ronald Reagan National Airport near Washington, prompting a large search-and-rescue operation in the nearby Potomac River. There were multiple fatalities, according to a person familiar with the matter, but the precise number of victims was unclear as rescue crews hunted for any survivors. Less than 30 seconds before the crash, an air traffic controller asks the helicopter if it has the arriving plane in sight: “PAT-25, do you have the CRJ in sight?” The controller makes another radio call to PAT25 moments later: “PAT-25 pass behind the CRJ.” At the approximate time of the collision, an air traffic controller is heard saying "did you see that?" The controllers quickly began redirecting flights to other airports in the region.