Lahar costs
Stephen Franks reminds us that while people jump with joy that the lahar did not destroy anything, the cost of the precautions were $10 million, as opposed to a maximum cost of $200,000 to cut a small channel to drain it.
The irony also is that the lahar itself created a larger channel than the artificial one which would have been cut. But hey that’s okay because it is natural and didn’t offend any spirits.