The United States military is investigating whether hackers may have caused a Navy destroyer to go off course and crash into a merchant vessel on August 21 in the waters off Singapore, it was learned on Thursday.

Ten sailors were killed after the warship John S. McCain collided with a merchant vessel last month.

The guided-missile destroyer collided with the Alnic MC east of Singapore while approaching the city state on a routine port visit.

Vice Admiral Jan Tighe, the deputy chief of naval operations for information warfare, said the military is looking into whether the McCain’s computer systems were compromised, Foreign Policy reported.

Ten sailors were killed after the warship John S. McCain collided with a merchant vessel last month near Singapore. The image above of the McCain was taken on August 21

The military is adamant, however, that there was no hack of the systems aboard the USS Fitzgerald.

The Fitzgerald is a destroyer similar to the McCain which also collided with a merchant ship near the Philippines on June 17.

‘With the McCain incident happening so close to the Fitzgerald,’ some have wondered whether a cyber attack is to blame, Tighe said.

While the Navy has already ruled out a hack as the cause of the Fitzgerald crash, it is now asking investigators to clear up doubts about the McCain.

Thus far, any talk of a cyber attack on the McCain is pure speculation, though military officials acknowledge that hackers could conceivably break into the ship’s computers and manipulate instruments to alter ship locations.

The McCain collision happened at night, so if there was a hack it would be conceivable that it would cause such a crash.

The U.S. Navy destroyer John S. McCain sails to Changi Naval Base in Singapore after the collision on August 21

Tighe said that the Navy is making efforts to shore up its cyber defenses.

Seventeen sailors died in total from the two collisions.

The Navy ordered a halt to operations after the McCain collision and called for a review of safety protocols.

The Navy last month removed Seventh Fleet Commander Vice Admiral Joseph Aucoin from his post, citing ‘a loss of confidence in his ability to command’ after the run of accidents.

Rear Admiral Phil Sawyer takes command of the fleet from Aucoin, who had been due to step down next month.

The Seventh Fleet, headquartered in Japan, operates as many as 70 ships, including the U.S. navy’s only forward-deployed aircraft carrier, and has about 140 aircraft and 20,000 sailors.