Chicago, Illinois (CNN) -- A coroner's office plans to conduct autopsies Thursday on four people who were found dead in a home in suburban Chicago.
A man, a woman and two boys were found dead Wednesday in a house in Addison, Illinois, just west of Chicago, according to a statement from the DuPage County Coroner's Office.
CNN affiliate WGN identified the four as 48-year-old Thomas Mangiantini, his wife Elizabeth, 46, and the couple's two sons, Angelo and Tommy. The station said Mangiantini was a printer and a baseball coach in Addison.
A preliminary investigation indicates that the incident "is isolated to this address," and "resident(s) should not be alarmed that further acts of violence will occur as a result of this incident," the coroner's office said in a statement.
Investigators found shell casings near the bodies, Addison Police Chief Tim Hayden said Wednesday, but the cause of death was still under investigation, WGN reported.
Police received a 911 call from a woman at 6:30 a.m. Wednesday, WGN said. When officers arrived they found a female dead downstairs and the bodies of three males upstairs, according to WGN.
The Mangiantinis put out their Christmas decorations the day before they were found dead, the station reported.