A woman and her two daughters were walking along the Mystic River around 4:30 p.m. with their black lab, Lucy, when officials say Lucy spotted swans in the middle of the river and broke away to run onto the ice. The ice gave way and Lucy plunged into the frigid waters, unable to get herself out.
Arlington firefighters wearing "warm suits" were able to head onto the ice to rescue Lucy, briefly falling through the ice themselves.
Lucy was checked out by Arlington EMS and was able to be reunited with her family.
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