PLATTSBURGH — Two people died in car accidents during the mid-April storm that hit the North Country with a mix of heavy snow, rain and sleet.Near Keeseville, a young mother was killed and her baby seriously injured in a crash on the Northway Sunday night.In Chazy, a Quebec woman died when she was thrown from the van she was riding in as it flipped over on the Northway.State Police in Plattsburgh said 27-year-old Sara Rosen of Maryland was in a rear passenger seat of a 2007 Toyota minivan driven by her husband, Dovid Rosen, when it skidded off the southbound lane of Interstate 87 near exit 34 and hit a tree.The accident happened at about 5:15 p.m. in the Town of AuSable. Two-month-old Malkah Rosen sustained severe head injuries in the crash, according to police.She was brought to CVPH Medical Center in Plattsburgh and then transferred to Fletcher Allen Health Care in Burlington.Mrs. Rosen had temporarily unbuckled herself and the baby, State Police said.The mother was breast-feeding the child, according to emergency officials.The accident was blamed on speed unsafe for conditions, police said, but no tickets were issued.Members of the AuSable Forks Ambulance squad sent two ambulances, and another one came from Peru Ambulance Service, said Keeseville Emergency Medical Technician Deb Winter, who attended to the infant.The side door of the van was open when emergency personnel arrived. “We believe the mother was partially ejected,” Winter said.Mr. Rosen sustained a cut above one eye but refused treatment. Two other children in the van, ages 3 and 6, were brought to CVPH, where they were treated and released, according to hospital spokeswoman Chris Blake, who confirmed that the baby was transferred to Burlington.Fletcher Allen did not have any information available about the infant’s condition Monday morning.Driving conditions at the time were very poor, Winter said. “It was a heavy, wet snow in below-freezing temperatures. Visibility was difficult in the snow.”Multiple callers were able to report the accident from cell phones. Service in the northern exits of I-87 is more reliable than in central sections from exit 33 south to about Pottersville.Winter said Mr. Rosen may have placed one of the calls. “We were called by the dispatcher,” she said.An off-duty nurse and her husband were in one of the first cars to come upon the accident and stopped to render assistance, Winter said.The Rosen family are members of the Orthodox Jewish community and were traveling south from Montreal.The Hasidic ambulance service in Montreal came to recover Mrs. Rosen’s body.The accident is the third in about nine years to result in the death of either a mother or a child unbuckled from car-restraint systems to breast-feed, Winter said.Around 8:22 p.m., Jean Lafranc, 56, of Montreal, was driving a 2000 Ford north on I-87 when he tried to pass another vehicle.The vehicle went out of control, slid off the west side of the highway and rolled over twice.Passenger Jocelyne Toussaint, 57, of St. Rose, Quebec, was thrown from the vehicle and killed.She was pronounced dead by Clinton County Coroner David Donah, and her body was taken to the CVPH Medical Center.Another passenger, Raymonde Lorgis, 52, was also ejected. He suffered a neck injury and was taken to CVPH, where he was listed in stable condition Monday.Police said Toussaint and Lorgis were not wearing seatbelts.Five other passengers in the vehicle suffered neck, shoulder and back injuries and were taken to the hospital for treatment. Lafranc, the driver, was ticketed for speeding.