REPORTER: THESE HELICOPTERS COULD BE SEEN AND HEARD, NOT ONLY IN DOWNTOWN LOS ANGELES, BUT IN SURROUNDING AREAS AS WELL. PEOPLE WERE STARTLED TO SEE THESE MILITARY AIRCRAFT MANEUVERING SO LOW TO THE GROUND. A HELICOPTER FLYING LOW IN BETWEEN BUILDINGS IN DOWNTOWN LOS ANGELES.>>WE DON’T THINK IT WAS MUCH HIGHER THAN THE CHURCH. THEY WERE VERY LOW.>>YOU COULD SEE INSIDE. I’M JUST ASSUMING IT WAS THE CONTROL BOARD INSIDE. REPORTER: ERICA AND LESLIE WERE IN LINCOLN HEIGHTS. THEY SAW THE HELICOPTERS AND SAY THEY WERE ALLOWED.>>THE LIGHTS ARE ALL TURNED OFF. THERE WAS ONLY RED LIGHTS IN EACH ONE OF THEM. THEN ANOTHER HELICOPTER CAME IN. REPORTER: ACCORDING TO THE LAPD, IT IS PART OF A U.S. ARMY TRAINING EXERCISE TO TEACH SOLDIERS HOW TO OPERATE IN AN URBAN ENVIRONMENT. OFFICIALS SAY THE LOCAL TERRAIN IN LOS ANGELES PROVIDES THE ARMY WITH UNIQUE LOCATIONS AND ENVIRONMENTS. SOME PEOPLE HERE FEEL THEY SHOULD HAVE BEEN WARNED ABOUT THIS.>>IT WOULD BE NICE TO GET A HEADS UP. NOWADAYS YOU NEVER KNOW WHAT IS HAPPENING. EVERYBODY HAS A FEAR, ESPECIALLY AFTER 9/11, WHEN YOU SEE HELICOPTERS OR AIRPLANES FLYING LOW. REPORTER: A STATEMENT BY THE LAPD SAID, THIS TRAINING IS COORDINATED WITH THE APPROPRIATE OFFICIALS AS WELL AS PRIVATE PROPERTY OWNERS.