Air ambulance service provided by Lifenet has resumed after all helicopters were grounded following an accident involving the Douglas crew in Tucson.

Four of the company’s seven helicopters are back in the air, and the remaining three should be released later this week.

Flights were halted on Friday, August 30, following a crash Wednesday, July 28, that killed the pilot, nurse and paramedic on board the flight. The helicopter crashed in a northside Tucson neighborhood. Killed Wednesday were pilot Alex Kelley, 61; paramedic Brenda French, 28; and flight nurse Parker Summons, 41.

There were no patients on board.

The helicopter crashed into a fence and shed at about 1:45 p.m. Wednesday.

According to reports, French, who began working for LifeNet Arizona in March, died at the scene. Kelley, an employee since 2002, and Summons, who had worked for LifeNet since 2007, died at University Medical Center, company officials said.

"This is a sad day for all of us at Air Methods and we extend our heartfelt sympathy to the family and friends of our employees who perished while on duty," said Aaron Todd, chief executive officer of Air Methods Corporation."

“The citizens of the Douglas Community offer the most hear felt condolences to the families who have suffered such a tremendous loss. The loss of what I consider a family of our community. These professionals were dedicated to saves lives in our community. Our prayers are with them and their families,” said a statement from Douglas Mayor Dr. Michael Gomez and the City Council.

The helicopter was returning from Marana when the accident occurred.

Investigators from the National Transportation Safety Board and the Federal Aviation Administration were on site last Thursday to conduct its investigation.

There currently is no timeline for a report on the investigation.