According to a New York Times report, The Pentagon said today that a system it uses to detect the flashes of explosions around the world did not detect any such flash anywhere in the region on the night that Malaysian Airlines Flight MH370 disappeared.

The Malaysian military has denied that its radars tracked the missing Malaysian Airlines plane over the Straits of Malacca. Previous reports said that it had tracked the plane flying at low altitude over the straits, which gave rise to the idea that hijackers might have been attempting to fly it under radar coverage, perhaps in an attempt to carry out a 911-style attack on an Indian city.

Search teams have broadened the search area to include much of the South China Sea and the Straits of Malacca, despite the fact that the Malaysian military has now denied reports that it detected the plane over the straits.

It can take days to find a crashed airliner, but it is very unusual for large aircraft to go permanently missing. While a number of small planes have been lost either at sea or over isolated areas in recent years, no plane the size of a Boeing 777 has ever been lost, and so far it is still anticipated that the plane will be found at some point.

The last large airliner to disappear without a trace was Flying Tigers Flight 739, a Lockheed Constellation that disappeared without a trace over the Western Pacific Ocean on March 15, 1962 with 107 people on board. The plane was never found, and it was assumed that the cause had been a massive onboard explosion–exactly the kind of explosion that would have been detected by the Pentagon’s system, had Flight MH370 exploded.