"The pain is very strong," Manuel Quizhpi, who said he was the brother of one of the victims, told The Chicago Tribune.
None of the minivan's 10 occupants were wearing seatbelts during the crash Thursday night on the Indiana Toll Road about 10 miles east of South Bend, state police Sgt. Trent Smith said. Smith said the infant, who the Tribune said was a 1-month-old boy, was in a car seat but had not been buckled in.
Quizhpi told the Tribune all of those on board were Ecuadoran immigrants living in Chicago's Albany Park neighborhood.
He said six adults and four children were in the minivan, including the baby's father, a construction worker in his early 30s, who was driving. Quizhpi said the driver was in a coma and his wife was killed. Others in the van included a 9-year-old boy, an 8-year-old girl and a boy either 15 or 16, he told the newspaper.
Quizhpi declined to give the names of the victims. Smith said family members were coming about 100 miles from the Chicago area on Friday to help identify them.
The semitrailer was going about 65 mph when it hit the van in the highway's eastbound lanes shortly after the van struck a deer and stopped or slowed down about 8 p.m., Smith said. Both vehicles ended up in the center median, blocking traffic in both directions for several hours.
Firefighters and emergency workers at the scene of the crash swarmed around the crumpled remains of the minivan, its side shredded with a torn hunk of metal pinned beneath one of the semi-tractor's tires.
Two of the minivan's three injured occupants - a man and a woman - were taken by helicopter for treatment and were in critical condition Friday. Another man was in stable condition, Smith said.
Preliminary tests indicated that the trucker - Jesse Donovan, 24, of Johnston, R.I. - had not been drinking alcohol, Smith said. Donovan was released was a hospital after treatment for minor injuries. Smith said Donovan didn't face any charges at this time.
Donovan was an employee of Roehl Transport Inc. of Marshfield, Wis., which owns the truck, said Vice President of Workforce Development and Administration Greg Koepel.
"Our hearts go out to those in the accident and their families," said Koepel, who said the company would have no further comment.