TN has a strong felony murder statute. You dont need to prove intent, you just need to prove they were perpetrating a related violent felony.
I'm not a lawyer but in this case it seems like management have probably met the criteria for felony theft or kidnapping. Any properly motivated DA could then add a felony murder charge for each death.
Section 1751(a) of Title 18 incorporates by reference 18 U.S.C. §§ 1111 and 1112. 18 U.S.C. § 1111 defines murder as the unlawful killing of a human being with malice, and divides it into two degrees. Murder in the first degree is punishable by death.