It swayed and trembled as a terrific crash rent the air.

The tepee toppled over at the same instant, leaving the Overland girls lying in the open.

Tom and Hippy, at the time asleep in their lean-to, which was a few yards nearer the river, never were able to decide whether they had been hurled from their beds or had leaped out before they were fully awake.

At least, they found themselves outdoors, and some yards from the lean-to.
"For the love of Mike, what now ?" gasped Hippy.
Hindenburg was running about in circles, uttering dismal howls, and the pet bear was scrambling for the top of the highest tree in his vicinity.
"It's the dam!" shouted Tom Gray.

"They've got us this time!" growled Tom, starting down the bank, followed by Hippy and the yowling bull pup.
Hippy saw a figure running from the bank of the river a little further upstream.