Signs not seen in campsites at home

This sign was in the site in the Tongariro National Park.

'Lahar' is, I'm told, an Indonesian word for the mudslide that occurs when a volcano erupts and debris mixes with water in the crater.
The 'Skotel assembly point' was the motel down the road, and on the other side of it, from the site.
I managed to dismiss the sign as just health and safety over caution otherwise I might not have slept while there. However, while doing the Crossing walk we saw evidence of past mudslides and current volcanic activity. Then, after leaving the site we were only a few kilometres down the road when we stopped for a break at Tangiwai beside a gentle, shallow river, and came across a memorial to 151 people who died in an incident late on Christmas Eve 1953. A lahar from Ruapehu weakened a railway bridge over the river at this spot and an express train from Auckland to Wellington plunged into the flood water.