Recovery crews were searching on Friday for the scattered wreckage of a sightseeing helicopter that appeared to break apart over the Hudson River the previous day before slamming into the water, killing all six people on board.
Among the pieces that had not been found by Friday afternoon was the main rotor, according to Jennifer Homendy, the chair of the National Transportation Safety Board. Videos filmed by witnesses showed the part flying off the helicopter as it plunged into the river.
As she cautioned that the investigation was just beginning, Ms. Homendy would not speculate on what had caused the crash. A typical investigation can take a year or two to complete, according to the agency.
“Everything is on the table — we don’t rule anything out,” she said at a news conference with officials from Jersey City, near the site of the crash, on Friday afternoon. She did not offer a timetable for the investigation.