What were the circumstances behind the Caroline Incident?

The steamboat Caroline was a hostile vessel engaged in piratical war against her Majesty's people...it was under such circumstances, which it is to be hoped will never recur, that the vessel was attacked by a party of her Majesty's people, captured and destroyed.

Explanation: On December 29, 1837, while the Canadian rebels were on Navy Island, Canadian loyalist Colonel Sir Allan MacNab and Captain Andrew Drew of the Royal Navy commanding a party of militia, acting on information and guidance from Alexander McLeod that the vessel belonged to Mackenzie, crossed the international boundary and seized the Caroline, chased off the crew, towed her into the current, set her afire, and cast her adrift over Niagara Falls, after killing one black American named Amos Durfee in the process

answer; code of federal regulations;