Source: Timeline
Nov. 11, 1918 Armistice ending World War One is signed on behalf of Germany at Compiègne in France by Matthias Erzberger at the instruction of German army commanders Hindenburg and Ludendorff.
Pacelli cables Gasparri requesting instructions, because Archbishop Faulhaber has told him that his life is in danger and he should go to Switzerland; Faulhaber also requests the Pope to intervene with President Wilson to stop the Allied blockade of Germany. English translation - Italian original at www.Pacelli-Edition.de, Document No. 6092
Faulhaber later writes that he recommended Pacelli go to either Rorschach or Menzingen in Switzerland. German original at www.Pacelli-Edition.de
Nov. 13, 1918 Gasparri cables Pacelli, authorizing him to go elsewhere as advised by Archbishop Faulhaber, namely to Rorschach in Switzerland, in light of the uncertain situation in Munich.
Source: www.Pacelli-Edition.de, Document No. 2449
Nov. 11, 1918 Nuncio Pacelli from Munich to Cardinal Gasparri in Rome, by encrypted telegram:
His Excellency the Archbishop of Munich came to me and represented to me that if the Armistice clause about the continuation of the blockade of Germany should remain in effect, it appears that hundreds of thousands of city dwellers, in Belgium alone, could die of hunger, and this would work a horrific catastrophe. He therefore supplicates His Holiness to take opportune steps with the President of the United States and the Entente governments to forestall such a tremendous misfortune.
The same Most Excellent Archbishop, considering that my person is exposed to near and grave danger, has confidentially suggested to me that I should betake myself to Swiss territory; Your Most Reverend Eminence may wish to deign to impart opportune instructions, both for me and for the personnel of the Nunciature.
Source: Historical Archive of the Secretariat of State (Holy See), Section for Relations with States, Vatican Secret Archives, AA.EE.SS., Stati Ecclesiastici, 1914-1918, pos. 1317, fasc. 470, vol. XII, fol. 390r, reprinted at www.Pacelli-Edition.de, Document No. 6092.