WASHINGTON (AP) — Federal safety inspectors say baby formula maker Abbott failed to maintain sanitary conditions at the Michigan manufacturing plant recently linked to a cluster of infant illnesses. The Food and Drug Administration began investigating the plant after Abbott recalled several leading infant formulas. The products have been tied to four infant hospitalizations, including two deaths, due to a rare bacterial infection. FDA inspectors released their initial findings Tuesday evening. Among other problems, they found a history of contamination with the bacteria in various parts of the plant. But the FDA report doesn’t identify a root cause for the latest outbreak.