<p>"[Though the damage caused by strip-mining was often irreparable to the natural environment, it] was once used to supply half the coal produced annually in the United States."
*I know this sentence is incorrect because I think "it" is referring to "damage"... and that can't be right because "strip-mining" should refer to "it"... right?</p>
<p>"[Though strip mining often caused irreparable damage to the natural environment, it] was once used to supply the coal produced in the U.S."
*I think this is right, but.... I get really confused when there is a comma and then something right afterwards like in this sentence, couldn't "it" be referring to "environment" because it comes right before it? Isn't that like a rule for dangling modifier/referring to pronouns? (I get confused with those kinds of 'reference/modifier' rules)</p>
<p>Help!</p>