How the drama unfolded:
One of three DOC sensors at Crater Lake registers unusual earth vibrations.
The same sensor sounds another warning
The same sensor repeats another warning
The other two sensors at Crater Lake start sounding. The lahar is thought to began to occur at this point, over a period of about 45 minutes.
Police announce closure of SH1 between Rangipo and Waiouru. SH49 between Waiouru and Ohakune is also closed. All rail services stopped at Waiouru and Ohakune.
DOC sensors return to their normal background reading.
Whangaehu River levels peak just after 1.
SH1 between Rangipo and Waiouru reopened.
SH49 between Waiouru and Ohakune reopened
Tangiwai rail bridge reopened subject to a 25 kph speed limit