[3][4] Possessing the "rare pitch of a true alto",[5] she frequently appeared as Erda in Wagner's Der Ring des Nibelungen at the Leipzig Opera, Schwertleite in Die Walküre at the Teatro Comunale di Firenze with Zubin Mehta, and in Mahler's Symphony No.

Radner, her husband, and her infant son were among the 150 people killed in March 2015 when Germanwings Flight 9525 was deliberately crashed by its co-pilot, Andreas Lubitz.

[10] Her talent for singing remained unnoticed at school, but when she was 14, her parents introduced her to voice teacher Angelo Melzani, who told her, "I will get you into opera.

[10] Radner's father obtained additional voice lessons for her with Jeannette Zarou in Düsseldorf and later with mezzo-soprano Marga Schiml, both experts in early music and Lieder, who recognized her as a contralto.

Radner was still a student in 2008 when she made her first public appearance under Zubin Mehta at the Palau de les Arts Reina Sofia in Valencia, singing Martin y Soler's oratorio Philitaei a Jonatha disperse.

[5] In 2009, she performed in a new production of Parsifal under Lorin Maazel in Valencia and in Arthur Honegger's Jeanne d'Arc au bûcher under the direction of Antonio Pappano at Accademia Nazionale di Santa Cecilia in Rome.

[15] After graduating with distinction, Radner performed Schumann's Faust scenes under Jesús López-Cobos at the Teatro Real Madrid.

[15] In October 2010, she appeared as Dryad in Ariadne auf Naxos at the Theater an der Wien, conducted by Bertrand de Billy.

At the Salzburg Festival in July and August she was "a voice from above" and a servant in Richard Strauss's Die Frau ohne Schatten under Christian Thielemann.

[9] In January 2013, Radner appeared as the valkyrie Schwertleite in Die Walküre at the Teatro Comunale di Firenze under Zubin Mehta, and in March she again portrayed Erda in Das Rheingold, conducted by Ingo Metzmacher at the Grand Théâtre de Genève.

[17] She traveled to Bucharest in September, where she sang Erda in a concert performance of Das Rheingold with the Radio Symphony Orchestra Berlin under the direction of Marek Janowski.

[21] Radner gave her final performance as the earth goddess Erda on 23 March 2015 in Wagner's Siegfried at the Gran Teatre del Liceu in Barcelona.

"[3] Stern described photos of her private life, published one week prior in Bild, showing the young woman embraced by her partner Sascha Schenk in the soccer stadium with a scarf of FC Bayern Munich, and him holding their infant son, who is sitting on a motorbike.

[1] Radner died on 24 March 2015, along with her husband Sascha Schenk, their 18-month-old son Felix,[1] and her colleague Oleg Bryjak, when Germanwings Flight 9525 crashed near Prads-Haute-Bléone, Alpes-de-Haute-Provence, France.

[25] They were en route to Düsseldorf after Radner's and Bryjak's two performances in Wagner's Siegfried at the Gran Teatre del Liceu in Barcelona.

[26] The Metropolitan Opera issued a brief statement, mourning her "untimely and tragic death" and calling her "a gifted artist who touched the lives of many".