Complex sentence: There are currently an additional thirteen (13) portable classrooms situated on site for the 2008-2009 school year.But in fall 2007 some of the portables burned down, now there is no portable one, which was the first one to be burn down.
Split into simpler sentences: There are currently an additional thirteen (13) portable classrooms situated on site for the 2008-2009 school year. In fall 2007 some of the portables burned down, now there is no portable one, which was the first one to be burn down.