There must be a finite number of memorial stèles in the Forest, but sometimes it doesn’t feel like that. On Saturday I passed one which I hadn’t encountered before, on the Drève des Tumuli near the junction with Saint-Hubert.

On this memorial is written:
BOSSAERT
ETIENNE
MORT
ACCIDENTELLEMENT
LE 31 MAI 1967

The only extra information I have found to date is this obituary from 𝐿𝑒 𝑆𝑜𝑖𝑟. I know nothing else, other than that he was 45 years old at the time of his death and that it was accidental.
