[Source: Reuters]

U.S. authorities restricted helicopter flights near Reagan Washington National Airport on Friday, after a midair collision between an American Airlines (AAL.O), opens new tab passenger jet and a military helicopter killed 67 people this week.

Investigators were able on Friday to recover the helicopter’s black box, which captures flight data and voices in the cockpit, National Transportation Safety Board member Todd Inman said at an afternoon briefing.

The information from the box, along with the cockpit voice recorder and flight data recorder from the CRJ700 airplane, could help authorities piece together what happened just before the two aircraft collided on Wednesday night and plunged into Washington’s freezing Potomac River in the deadliest U.S. air disaster in two decades.

The board has also conducted interviews with air traffic controllers, Inman said, including the lone controller working inside Reagan’s tower at the time of the crash on Wednesday.

Authorities have not identified a cause, and Inman said the board would not engage in speculation before completing its investigation.

Separately, a small private plane crashed near a shopping mall in Philadelphia on Friday evening, resulting in multiple casualties on the ground, local media reported.

U.S. Transportation Secretary Sean Duffy said on X that he was monitoring the incident and was headed to the Federal Aviation Administration to gather more details.

Following the Washington crash, the FAA sharply restricted helicopter flights near Reagan to reduce the risk of another collision, Duffy said earlier on Friday, confirming news first reported by Reuters.

Duffy said the decision “will immediately help secure the airspace near Reagan Airport, ensuring the safety of airplane and helicopter traffic.”

The FAA is barring most helicopters from parts of two routes near the airport and only allowing police and medical helicopters, air defense and presidential air transport in the area between the airport and nearby bridges.

The restrictions will last at least until the NTSB releases a preliminary report into the fatal collision, which typically takes 30 days. At that point they will be reviewed, Duffy said.

American Airlines CEO Robert Isom said the airline would work with the government “to make our aviation system even safer.”

Crews have recovered 41 bodies thus far, officials said. Pulling the debris from the Potomac River will begin “in earnest” on Sunday, Inman said, an effort that will likely last all week.

Washington, D.C., Fire Chief John Donnelly told reporters that 28 bodies have been positively identified and that he expected all victims would eventually be recovered.