WASHINGTON, June 16: The commission investigating the Sept 11, 2001, attacks in the United States concluded US air defenses were disastrously unprepared for a major terrorist strike.

The preliminary report, published by the New York Times and scheduled to be released on Thursday, said the response by the military, civil aviation authorities and other agencies was too slow and confused to prevent three hijacked airliners from flying into the World Trade Center and the Pentagon, the Times said.

"On the morning of 9/11, the existing protocol was unsuited in every respect for what was about to happen. What ensued was a hurried attempt to create an improvised defense by officials who had never encountered or trained against the situation they faced," the Times quoted a passage of the report as saying.

It said the report suggests, although does not explicitly state, that a fighter aircraft may have been able to reach one hijacked airliner and shoot it down before it crashed into the Pentagon had the North American Aerospace Command had a more organized response.

Instead, an emergency order by Vice President Dick Cheney authorizing that the hijacked planes be shot down did not reach the pilots until after the last of the four commandeered aircraft crashed in Pennsylvania, the paper said. -AFP