The B-17 Flying Fortress that crashed during the Wings Over Dallas WWII Airshow was one of the last of its kind built by Douglas Aircraft Corporation at its Long Beach plant during World War II.

Named the Texas Raiders, the historic bomber collided with a Bell P-63 Kingcobra fighter in midair Saturday, crashing at Dallas Executive Airport and killing six members of the Commemorative Air Force.

“On behalf of its board, staff and members, the International Council of Air Shows offers its heartfelt condolences to the families of those individuals involved in the recent accident in Dallas and to our colleagues in the Commemorative Air Force,” the ICAS said in a statement.

The Commemorative Air Force on Monday morning identified the flight crews involved in the crash as Terry Barker, Craig Hutain, Kevin “K5” Michels, Dan Regan, Leonard “Len” Root and Curt Rowe.

No spectators were hurt in the crash.

With a nearly 104-foot wingspan, the 74-foot-long, 65,500-pound bomber was one of the most iconic aircraft that served during the war. B-17s were present at both Pearl Harbor and Clark Airfield in the Philippines, making them some of the first U.S. aircraft committed to combat—and the first to suffer losses—according to the Commemorative Air Force Gulf Coast Wing website.

Beginning in 1935, 12,726 B-17s were produced by Boeing, Douglas and Lockheed for the Allied forces, according to Boeing.

Over the course of the war, B-17s dropped a greater tonnage of bombs on Axis power-occupied Europe than any other aircraft. Texas Raiders was built by Douglas under license from Boeing on July 12, 1945, the last day of Fortress production at the Long Beach plant and less than two months before the war would come to an end.

Over 4,700 B-17s were shot down during the war, according to the Experimental Aircraft Association. Most of the remaining bombers were scrapped, with fewer than 100 airframes remaining and fewer than 15 still capable of flight.

After the war, the bombers became obsolete and many were scrapped and melted down to make consumer goods. Like the rest of the bombers built near the end of the war, Texas Raiders was to be unceremoniously scrapped shortly after delivery, according to CAF. Fortunately for the aircraft, it was one of 20 selected for the U.S. Navy’s Cadillac II project, which strived to take the existing short-range airborne combat radar system and create a long-range capabilities.

The project considered three different aircraft for the project based on size and capability, including the B-24, C-54 and B-17, according to Steeljaw Scribe. The B-24 was eliminated first due to its high-mounted wing and low ground clearance. Ultimately, the B-17 was chosen over the C-54 because the projected area of operations were combat zones and the aircraft had already proven itself as reliable in battle.

Cadillac II led to the world’s first successful attempt at what is now known as Airborne Early Warning and Control. An AEW&C is an airborne radar system designed to detect aircraft, ships, vehicles, missiles and other incoming projectiles at long ranges. The systems also direct fighter and other attack aircraft strikes, and carry out surveillance.

Texas Raiders served the Navy until 1955, at which point it was retired to an Arizona boneyard. It was once again saved from the scrap pile, though, when Aero Service Industries bought the aircraft in 1957 for aerial survey, high-altitude photography and aerial mapping.

Texas Raiders continued to serve the private sector for a decade before the CAF, which was chartered as a nonprofit Texas corporation to restore and preserve World War II-era combat aircraft in 1961, struck a deal the purchase the plane in 1967. Texas Raiders became the first B-17 to come into the possession of the organization, which is dedicated to “education and the preservation of history.”

For decades, the Texas Raiders wowed crowds as a fixture of the airshow circuit. The aircraft was a “keystone” of CAF’s fleet, touring the country for over half a century before crashing in Dallas.

The cause of the crash is currently under investigation.

National Transportation and Safety Board member Michael Graham during a news conference Sunday offered his condolences to the families of the crew members and said the organization will “methodically” and “systematically” review all evidence and factors to determine a probable cause, according to an NBC DFW report.

“This is the beginning of a long process,” said Graham, noting that a preliminary report would take four to six weeks, while the full investigation will take 12 to 18 months.

“Basically, we’ll look at everything that we can and we’ll let the evidence basically lead us to the appropriate conclusions,” Graham said. “But at this point, we will not speculate on what happened.”

Brandon Richardson is a reporter and photojournalist for the Long Beach Post and Long Beach Business Journal.