POTTSVILLE, Pa. (AP) — Authorities say genetic material will be needed to positively identify the six people killed during an 80-vehicle pileup on a Pennsylvania interstate during a snow squall last month.

Dr. David Moylan III, the Schuylkill County coroner, told The Pottsville Republican-Herald on Friday that “we need to get some DNA samples” from relatives of the four men and two women killed in the March 28 crash on I-81.

Officials said earlier that the victims of the March 28 crash near the Minersville exit of I-81 were all between 40 to 70 years old and all burned beyond recognition. Two dozen people were injured.