Five people were found shot dead in a suspected murder-suicide at a home owned by retired veterinarians and their son in a notoriously safe suburban-Chicago village, according to reports.

The bodies of three men and two women — four of whom were relatives — were found in several different rooms in the home in Mundelein late Sunday, with the killer believed to be someone in a relationship with one of the slain family members, WLS reported. All five had been shot at close range with a handgun.

Neighbors in the village — where crime is 63% lower than the national average — assumed the gunshots were firecrackers being set off ahead of Sunday’s Chicago Bears game against the Atlanta Falcons, some told the outlet.

The bodies were only found when the elderly homeowners’ daughter called from some 2,000 miles away in California asking for a welfare check, the outlet said.

Authorities have yet to confirm the identities of the dead. However, the home was owned by retired vets Rebecca Schmidt, 77, and James Schmidt, 80, and their son Bryan Schmidt, 51, who ran their now-shuttered cat clinic, NBC5 said.

Neighbors feared the elderly couple and two of their relatives were among the dead, calling it a shock because they were all “very quiet people.”

“She was a spry, retired veterinarian,” one neighbor said of Rebecca Schmidt. “She was a friendly person. She’d wave to people. She’d have conversations with all kinds of neighbors.”

The four relatives are believed to have been killed by someone in a relationship with one of them, police told the Daily Herald.

Two guns were found at the scene and a gray Volkswagen Jetta parked in a neighboring funeral parlor was sealed off by investigators.

The shocking scenes disturbed residents in Mundelein, a notoriously safe area named after a man of peace, former Archbishop of Chicago George Mundelein.

“It’s a really safe, small town, So hearing this, five people dying, it’s kind of concerning,” Pavli Ibarra, a neighbor told WLS.

“Nothing like this happens around here,” neighbor Debbie Wunluck, who described the slain couple as “quiet people,” told the Daily Herald.

Autopsies are being carried out and investigations are continuing.

If you or someone you know is affected by any of the issues raised in this story, call the National Suicide Prevention Lifeline at 800-273-TALK (8255) or text Crisis Text Line at 741741.

If you are struggling with suicidal thoughts, you can dial the 24/7 National Suicide Prevention Hotline at 988 or go to SuicidePreventionLifeline.org.