Roncalli Principal Chuck Weisenbach said the girls' father, Doug Opel, was a former Assistant Football Coach and Athletic Director at Roncalli High School.
"We are deeply saddened to have lost two members of our Roncalli family," said Weisenbach. "Mallory Opel, Class of 2009 and Meredith Opel, Class of 2015. The Opel Family spans generations of Roncalli alumni and have been long time members of our community on many levels. Our hearts are heavy and our prayers are with the family."
The deaths remain under investigation by the Indianapolis Metropolitan Police Departments.
If you have any information on this case, call Crime Stoppers at (317) 262-TIPS.