This is the 9370th most frequent Japanese word.
破ら
"破ら" is the stem form of the verb "破る" (yaburu), which means "to break," "to tear," or "to violate."
破られ here means 'to be torn,' referring to physical damage done to the letter.
手紙が破られていました。
The letter was torn.
破ら here means 'to break,' referring to violating rules.
彼はルールを破りました。
He broke the rules.
破られた indicates 'to be broken,' referring to overthrowing a record.