Book:
Centenary of BASF - In the Realm of Chemistry
(c) 1965 by Econ-Verlag GmbH, Dusseldorf - Vienna

Photo page 92-93. Oppau factory after the explosion on 21st Sept 1921, at 7.30 am.
Photo attributed to Compagnie Aerienne Francaise.


https://en.wikipedia.org/wiki/Oppau_explosion

The Oppau explosion occurred on September 21, 1921, when approximately 4,500 tonnes of a mixture of ammonium sulfate and ammonium nitrate fertilizer stored in a tower silo exploded at a BASF plant in Oppau, now part of Ludwigshafen, Germany, killing 500–600 people and injuring about 2,000 more.