Statement
Boryslav, captured on 1 July 1941, held 14,000 Jews; the 4 July massacre killed over 800, according to one of 400 survivors.
Documented evidenceHigh certainty✓ Verified
References
p. 436
supports · main text · ch. 14
Efron, Lehmann and Weitzman. The Jews: A History. 3rd edition. New York and Abingdon: Routledge, 2019.
Verification anchor recorded · checked against the page text