(Indiana State Police)
Inside, the woman and the couple's two young children were found dead in separate bedrooms. Investigators were probing whether the man killed his family then committed suicide by driving the wrong way on an interstate highway in neighboring Indiana, instantly killing a stranger, too, as he slammed into the man's car.
Police agencies in Michigan and Indiana spent the day trying to connect the dots. Authorities said they hadn't turned up any suicide notes from Michael VanDerLinden, 39, who was killed in the fiery crash some 200 miles from the home where his family members were found dead.
"We have no other leads to push us to any other suspects. It's one of those puzzles you have to put together," said Gregory Laurain, the police captain in Van Buren Township, Mich. "There is a lot of speculation right now that it could possibly be the father. We want to get a taste of the relationship of the people who lived here. ... Were there problems here?"
VanDerLinden and the other driver, 45-year-old Juan Nelson Jr., of Portage, Ind., were killed in the pre-dawn crash on Interstate 94 near Michigan City, not far from the Michigan state line, said John Sullivan, the coroner in LaPorte County, Ind.
Indiana State Police say VanDerLinden had just left a highway rest area and was traveling eastbound in the westbound lanes of the freeway when he collided with Nelson's car, engulfing both in flames. The crash closed two westbound lanes of I-94 for several hours.
Police in the semirural Van Buren Township, about 25 miles west of Detroit, were asked by Indiana authorities to notify VanDerLinden's family about the crash. But when officers arrived about 8 a.m. no one answered the door at the home.
Neighbors told authorities that seemed odd.
"She was a stay-at-home mom and the kids are out from school. This time of morning there should be somebody here," Laurain said.
Officers went back to the house and found one of the doors unlocked.
Inside they found the bodies of the two boys -- identified by neighbors as 7-year-old Julien and 4-year-old Matthew -- in beds in their own rooms. Their mother's body was found in her bedroom.
"There were no signs of forced entry. No signs of robbery," Laurain said.
Public records showed VanDerLinden co-owned the house with his wife, 34-year-old Linda VanDerLinden.
Officials weren't confirming the identities of the bodies in the house. Laurain said a possible murder weapon was recovered, but he would not say how they were killed. Autopsies were scheduled for today.
Laurain said officials would go over the ripped and burned wreckage from the Indiana crash "to make sure nothing is there ... no type of notes." Computers, answering devices and other items were taken from the home Thursday.
Officers had not previously responded to the home on any reports of domestic violence, but firefighters were called out in November after Michael VanDerLinden took some type of pills in an apparent suicide attempt, Laurain said.
Laurain said Michael VanDerLinden had ties to Belgium and performed informational technology work from home.
Rita Jones, who lives next door to the family, said that while Linda VanDerLinden was friendly and outgoing, Michael VanDerLinden seldom made conversation with the neighbors.
"He was more, like, to himself," she said. "He wouldn't stay out and talk. He wasn't as friendly as she was."
Another neighbor, Litonya Hendricks, said she often saw the VanDerLinden boys playing outside their home.
"The whole purpose of moving out here is to get away from the crime," said the 31-year-old Hendricks who lives across the street. "You want to be around neighbors who can be trusted."
Associated Press writer Tom Coyne in South Bend, Ind., and AP news researcher Judith Ausuebel in New York contributed to this report.