LONGMONT, Colo. - A pilot whose plane crashed - possibly after a midair collision with another aircraft - was conscious when people ripped off the door of her Cessna 180 to pull her to safety, but authorities said two people in the other plane were killed.

The crashes of the single-engine planes north of Denver Friday - reported about five minutes and six miles apart - are being investigated as a possible midair collision, Federal Aviation Administration spokesman Mike Fergus said.

The two people who died appeared to be males and were believed to be an instructor pilot and a student in a Cessna 172 that crashed about a half mile from a Walmart southeast of Longmont.

"The tail end is literally in the nose of the plane," said Dustin Nelson, an oilfield services company employee who rushed to the scene after hearing the crash.

The survivor crashed within sight of the Vance Brand Airport runway in Longmont after clipping four overhead power lines. She was treated at a hospital and released, police said. The clipped lines caused 132 customers to temporarily lose power.

"It actually probably saved her because those lines reduced the impact into the ground," Longmont police Cmdr. Tim Lewis said. "The pilot did an excellent job of clearing the roadway and avoiding people who were picnicking and watching airport operations."

The engine separated from her plane on impact. One wing was crumpled and the tail was bent.

A few public works employees and passers-by hurried to help as her plane leaked fuel, Lewis said. "Get me out, get me out, get me out, help me out," Lewis said the woman told rescuers.

She complained of back injuries but was able to tell a fire lieutenant at the scene how to turn off the fuel pump, Lewis said.

The plane was registered to a Beverly Cameron, of Erie. A patient with that name was listed in good condition at Longmont United Hospital Friday afternoon.

Near the Walmart, Tom Ruddick was on a ladder painting oilfield equipment when he saw two planes that appeared to be about 300 yards apart and heading toward each other.

Nelson, who was working with Ruddick, was in his truck and heard what sounded like two backfires in the sky.

"It was a pop and about two seconds later, it was another pop," he said. Then he heard the engine rev up. "I seen that plane just nosedive straight to the ground just behind that house," Nelson said.

Ruddick had looked away from the planes but said he heard and felt what he believes was the shock wave from one plane crashing into the ground.

"It almost knocked me off my ladder," Ruddick said.

The other plane looked like it was having difficulty flying and even appeared to be "hovering," he said.

"It looked like he had no engine, like he was trying to pull up but he couldn't," he said.

Nelson, 25, of Longmont, said there was nothing he and his co-workers could do once they got to the crash scene. "Everything was crumpled into each other," he said.

Kim R. Johnson, who was in a parking lot off County Road 1, said the Cessna 172 appeared to have damage to one wing. He said it crashed with a thud.

"I was expecting an explosion, and it was just a big thud," he said.

He said the other plane banked, circled the crash site then headed west.

About six miles away, Don Poncelow had just landed at the Longmont airport after a training flight with an instructor pilot when he saw a plane coming in low.

"I looked up and I could tell she was having trouble. She wasn't out of control, but she wasn't in control, either," Poncelow said. "Something was just not right. She was having trouble keeping her wings level."

He said that after the plane clipped the power lines, it skidded across a road and crashed into a fence.

Carissa Muilenburg of Mile High Skydiving Center at the airport said one of their planes was landing around the time of the crash after ferrying skydivers to a drop.

She said the skydiving pilot reported there was a mayday call because of the incoming plane and he had to quickly get off the runway after landing.