What was the name of the U.S. Coast Guard heavy icebreaker that went out of service in 2010 due to the failure of its diesel engines?

What was the name of the U.S. Coast Guard heavy icebreaker that went out of service in 2010 due to the failure of its diesel engines?

USCGC Southwind
USCGC Glacier
USCGC Polar Sea
USCGC Burton Island
USCGC Polar Queen

The Answer: The correct answer is USCGC Polar Sea.