UPDATE: 7 Chicagoans Dead, Including Infant, In Indiana Toll Road Accident

UPDATED 10/28/11 3:30 p.m.

BRISTOL, Ind. (CBS) -- A deer is believed to be responsible for a crash on the Indiana Toll Road, which left seven Chicago family members, including an infant, dead.

The crash happened just before 8 p.m. in the eastbound lanes of the toll road between Bristol and Middlebury, Ind., in Elkhart County. Indiana State Police say a 1998 Toyota minivan registered from Chicago might have struck a deer, and come to a stop or slowed down in the driving lane, where the speed limit is 70 mph.

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The minivan was struck from behind by an east bound 2006 Freightliner semi-tractor trailer, state police said.

All ten occupants of the 1998 Toyota Sienna minivan with Illinois plates were family members from three different families -- the majority of whom lived in the Chicago area, Indiana State Police Sgt. Trent Smith said. Their addresses were not being disclosed Friday afternoon.

"They were cousins, uncles, nieces, that kind of thing,'' he said. "A few had passports or identification from Ecuador.''

Cayetano Quizhpe, 28, remains in "stable" condition at Elkhart General Hospital, but his wife and two sons -- Maria J. Yupa, 21, Edwin Quizhpe, 8, and Franklin Quizhpe, 6-weeks -- were killed, according to a release from Indiana State Police.

The infant was in a car seat that was not properly belted, according to Indiana State Police Sgt. Trent Smith.

Three members of another family were identified as Pedro Chimborazo, 52, and his son Pedro Chimborazo Yupa, 15, who were both killed.

Maria Antonia Yupa, 36, who is Pedro Chimborazo's wife and the boy's mother, is in serious condition at South Bend Memorial Hospital, the release said.

The driver of the minivan, Manual Chimborazo, 30, remains in critical condition at South Bend Memorial Hospital while his wife, 26, Maria Chimborazo Pinguil, and their daughter Jessica Chimborazo, 8 were killed, the release said.

The occupants of the minivan were headed from Chicago to New York, where they were planning to introduce the baby to his grandparents, the Chicago Tribune reported.

The family lived in the Albany Park neighborhood, the newspaper reported.

State police tell CBS affiliate WSBT-TV, South Bend, that the infant who was killed in the crash was in a safety seat, but was not restrained by a seat belt. No one else in the van had a seat belt on either, state police told WSBT.

Two people, including the truck driver, were taken to Elkhart General Hospital in Elkhart, Ind. Two others, a man and a woman, were taken by helicopter to South Bend Memorial Hospital in South Bend, state police said.

The truck driver was treated and released from the hospital, and a test for alcohol came back negative, state police said.

Traffic in the area was closed for several hours following the crash.

The truck was registered to Roehl Transport Inc. of Marshfield, Wis., although the truck driver, Jesse F. Donovan, 24, was from Rhode Island, state police said.

The Sun-Times Media Wire contributed to this report