Nakhon Ratchasima: a dramatic video of a rock slope collapse in a quarry in Thailand

A very interesting video has been published on Youtube showing a dramatic rock slope collapse of a quarry at Nakhon Ratchasima in Thailand.  Information about the origin of this video is patchy – the commentary states:

A lorry slammed his foot on the reverse pedal when an entire hillside collapsed at a quarry. Several trucks were loading boulders into their containers when the land suddenly gave way in Nakhon Ratchasima, northeast Thailand. Footage shows how the 30-metre tall cliff along with several trees crashed to the ground in a cloud of dust. Drivers quickly reversed to escape from the path of the flying debris. However, it was all cleaned up and secured afterwards.

Nakhon Ratchasima is located at 14.97, 102.08, but it is a large town, so I cannot identify the location beyond this.  The video should be visible below:-

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The video starts just after the initiation of the failure:-

The start of the quarry failure at Nakhon Ratchasima, northeast Thailand. Still from a video posted to Youtube.

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The collapse is a near-vertical fall, which suggests that the initiation might have been either undermining of the toe or the failure of a weak layer low on the slope.  It is interesting to note how the rock mass broke up as the collapse developed:

Further development of the quarry failure at Nakhon Ratchasima, northeast Thailand. Still from a video posted to Youtube.

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The dangers posed by the failure of even a comparatively small quarry slope are very clear.  It was fortunate that the truck was not close to the slope.