Phoenix ? People who saw two news helicopters collide and plummet to the ground while covering a police chase say the choppers did not appear to be in distress beforehand, investigators reported Saturday.

No one described any odd sounds before impact, and they didn’t see any smoke or debris from the choppers before Friday’s crash, which killed all four people aboard, said Steve R. Chealander, a member of the National Transportation Safety Board, which is investigating.

“It appears as though the Channel 3 helicopter was stationary and the Channel 15 helicopter came up either from under the Channel 3 helicopter, or was at the same level,” Chealander said. “Again, this is eyewitness testimony.”

The NTSB has interviewed about 30 witnesses, he said.

Investigators on Saturday picked through the charred wreckage, which was scattered about 100 yards in all directions and landed atop nearby buildings. They hoped to be done at the scene today and store the debris elsewhere in Phoenix.

Investigators will spend the next several days interviewing witnesses and reviewing maintenance records, Chealander said. They expect to issue a preliminary report in five business days and a full report within nine months.

On Saturday, investigators allowed reporters into the crash site.

The helicopters’ hulls were flipped over and squashed in two twisted heaps. The explosion blackened grass and trees. Curved metal sheets from the choppers floated upside down in a nearby pond.

The pond was laced with fuel from the helicopters, and the air was scented with burnt metal and aviation gas, Chealander said.

Helicopter parts were scattered all around: a foam seat; a disembodied tail rotor; small hunks of metal colored red, orange, yellow. Some parts sprouted frayed wires as if ripped from the engine.

The helicopters from TV stations KTVK and KNXV collided as both circled over the chase. Video from other stations showed white smoke trailing the choppers as they dropped into a grassy downtown park and exploded.

Killed on board the KTVK helicopter were pilot Scott Bowerbank and photographer Jim Cox. On board the KNXV aircraft were reporter-pilot Craig Smith and photographer Rick Krolak. No one on the ground was injured.

The NTSB will use a police hot line number to try to get witnesses to call in, Chealander said. Numerous people saw the helicopters drop to the ground.

Meanwhile, the man suspected of starting the chase was booked into jail on three counts of aggravated assault with a deadly weapon, two counts of theft and one count of resisting arrest.

Christopher Jermaine Jones, 23, also may be held responsible for the helicopter crash, police said.

Formal charges are expected to come later. At an initial court appearance, bail was set at $1 million.

According to court documents, Jones told officers that he didn’t remember stealing two trucks, ramming a police cruiser and leading officers on a chase through Phoenix. He said he woke up as officers were trying to arrest him at his friend’s house.