What is the origin of the lake tank image that has become a meme? (2021)

This entire deep dive is great. I feel compelled to call out this heroism:

> 1st Lieutenant de Wispelaere had prepared the bridge for demolition ... De Wispelaere immediately pushed the electrical ignition, but there was no explosion... Wispelaere now left his shelter and worked the manual ignition device. Trying to get back to his bunker, he was hit by a burst from a German machine gun and fell to the ground, mortally wounded. At the same time, the explosive charge went off.

This is also mentioned in the ConeOfArc video linked on stackexchange. However, at 4:17 in the video, the speaker shows a sign describing two versions of the event. In the first version, Wispelaere died due to a German shell (not a machine gun). In the second version, he was killed by the explosion of the detonating device after shortening the fuse (“l’explosion du dispositif de mise à feu”; not sure how to translate this exactly).