Quotation from: The Gods of Mars

Written by: Edgar Rice Burroughs

"This may explain the absence of the crew," he said.

It was a radio-aerial message to the commander of the submarine:

"The slaves have risen. Come with what men you have and those that
you can gather on the way. Too late to get aid from Omean. They
are massacring all within the amphitheatre. Issus is threatened.
Haste.