Everyone aboard an American Airlines jet carrying 60 passengers and four crew members that collided with an Army helicopter was feared dead in what was likely to be the worst U.S. aviation disaster in almost a quarter century, officials said Thursday. “We are now at the point where we are switching from a rescue operation to a recovery operation,” said John Donnelly, the fire chief in the nation’s capital. “We don’t believe there are any survivors.” At least 28 bodies were pulled from the icy waters of the Potomac River after the midair collision Wednesday night when the helicopter apparently flew in the path of the jet as it was landing at Ronald Reagan National Airport near Washington, officials said. Crews were still searching for other casualties but did not believe there were any survivors, which would make it the deadliest U.S. air crash in nearly 24 years. The body of the plane was found upside down in three sections in waist-deep water. The wreckage of the helicopter was also found. Donnelly said first responders on Thursday were searching an area of the Potomac River as far south as the Woodrow Wilson Bridge, roughly 3 miles (4.8 kilometers) south of the airport.