The Defense Department inspector general recommended the Army's Criminal Investigation Command reopen four of the cases -- including the most recent, in which Staff Sgt. Ryan D. Maseth was electrocuted in a shower in 2008. When Maseth, 24, a Green Beret from Pittsburgh, was killed, Sen. Bob Casey, D-Pa, pushed for the investigation.
Both Maseth and the first of 16 servicemen electrocuted were killed by an improperly grounded water pump, Stars and Stripes reported. Spc. Chase Whitham was killed in a recently renovated pool at a base in Mosul, Iraq.
The new investigations are hampered by lost evidence, lost leads and the U.S. pullback from some bases, the report said. Investigators have had a problem finding witnesses and collecting documents, Chris Gray, a spokesman for the Criminal Investigation Command said.
Investigators found some of the scenes of electrocution no longer existed, but also found at least one contractor who worked on a U.S. base without meeting even minimum standards, Stars and Stripes reported.
Notable deaths of 2014 [PHOTOS]