The three crew members of the MH-60R Sea Hawk helicopter were rescued on Sunday afternoon, and the two aviators in the F/A-18F Super Hornet fighter jet ejected and were recovered safely, and all five “are safe and in stable condition,” the fleet said in a statement.

The causes of the two crashes were under investigation, the statement said.

President Donald Trump, speaking to reporters aboard Air Force One en route to Tokyo on Monday, said the incidents could have been caused by “bad fuel.” He ruled out foul play and said there was “nothing to hide.”

The USS Nimitz is returning to its home port in Naval Base Kitsap in Washington state after having been deployed to the Middle East for most of the summer as part of the U.S. response to attacks by Yemen’s Houthi rebels on commercial shipping. The carrier is on its final deployment before decommissioning.

History of incidents

Another aircraft carrier, the USS Harry S. Truman, suffered a series of mishaps in recent months while deployed to the Middle East.

In December, the guided-missile cruiser USS Gettysburg mistakenly shot down an F/A-18 jet from the Truman.

Then, in April, another F/A-18 fighter jet slipped off the Truman’s hangar deck and fell into the Red Sea.

And in May, an F/A fighter jet landing on the carrier in the Red Sea went overboard after apparently failing to catch the steel cables used to stop landing planes and forcing its two pilots to eject.

No sailors were killed in any of those mishaps. The results of investigations into those incidents have yet to be released.