Three children and a woman were found dead in a Michigan home Monday after a fatal shooting, according to local media. The kids were all elementary-school age or younger, according to the Kent County Sheriff’s Office. “Certainly a horrific thing to be called to and my heart goes out to the families involved here and the community,” Kent County Sheriff Michelle Lajoye-Young told WOOD-TV. “We’re certainly going to do everything we can to bring this to a quick resolution.” The sheriff said authorities don’t believe there’s a shooter at large and that a murder-suicide was a possibility—but investigators are keeping an open mind, USA Today reports. Lajoye-Young added: “It’s always hard when there’s a death in the community, but it’s absolutely the most difficult when kids are involved.” The identities of the victims have not yet been confirmed.