Just off a trail in the woods on the Brastberg (Prestberg) Hill.

A large upright field stone with a brass inscribed plaque attached to the front. A small information sign stands adjacent to the stone.

The memorial remembers the B-24 (42-51132) of the 739th Bomber Squadron, 454th Bomber Group, 15th US Air Force that crashed here on July 20, 1944.  The aircraft flying from the San Giovanni Airfield in Southern Italy was on a mission to bomb the Maybach Complex in Germany.  On the return flight, the plane was hit by flak over Friedershaven, Germany.  The crew bailed out over Switzerland and survived; the plane crashed on this hill known at Prestberg (Brastberg).  The crew became Swiss Internees and one of the crew, Captain John Trautner, was reported to have escaped and returned to duty during the war.

The crew included:

Pilot: Franklin E. Tomlinson, Major
Copilot: William Henry, Jr., 1st Lt
Navigator: John J. Trautner, Cpt
Navigator: John C. Schreck, 1st Lt
Radarnavigator: William A. Crews, 1st Lt
Bombardier: Edward E. Matthews, Cpt
Engineer: Charles L. Putnam, S/Sgt
Radio: Rudolph J. Dualsky, T/Sgt
Asst. Engineer: John J. Faron, S/Sgt
Waist Gunner: Charles B. Smith, S/Sgt
Tail Gunner: Lelan H. Stringer, S/Sgt

Source of information: 

https://www.b17museum.ch

https://warbird.ch

Special thanks to the B-17 Museum in Utzenstorf, Switzerland, for the photos of this memorial and for information concerning this site.

The text on the plaque is inscribed in German and reads:

Prestberg-Illnau.

Absturz eines unbemannten

USA "Liberator"-Bombers.

20. Juli 1944. 

Translation: 

Prestberg-Illnau. Crash of an unmanned US "Liberator" bomber. July 20, 1944.

The information sign is written in German and reads:

Gedenkstein Brästberg
Am 20. Juli 1944, gegen Ende des Zweiten Welt-kriegs, stürzte an dieser Stelle ein amerikanisches Militärflugzeug in den Wald. Es handelte sich um einen B-24-Bomber, genannt Liberator".
. Er war
in einem Luftkampf über Süddeutschland angeschossen worden und hatte sich in die neutrale Schweiz geflüchtet. Die elf Mann zählende Besatzung konnte sich im Raum Weisslingen mit dem Fallschirm retten, bevor sich das herrenlose Flugzeug nach einem Gleitflug bei Brästberg in den Waldboden bohrte.

Translation:

Brästberg Memorial Stone

On July 20, 1944, towards the end of World War II, an American military aircraft crashed into the forest at this spot. It was a B-24 bomber, nicknamed "Liberator."

It had been shot down in an aerial battle over southern Germany and had fled to neutral Switzerland. The eleven-man crew managed to parachute to safety in the Weisslingen area before the derelict aircraft glided into the forest floor near Brästberg.