Deadly accidents on Northwest Indiana roads took five lives and left several people badly hurt Tuesday.

The dead included a pregnant woman whose SUV careened out of control on Interstate 65 and a father and daughter traveling to Michigan City in LaPorte County.

And while road conditions were not known to be a factor in any of the crashes, Indiana State Police on Tuesday urged caution as fluctuating temperatures first freeze and then melt water and snow, making roadways slick.

Amanda M. McRae, 25, of Portsmouth, Va., died at the scene of the early morning crash on I-65 between Lowell and DeMotte.

McRae, who was six months pregnant, was southbound on I-65 just before 5:30 a.m. when her sport utility vehicle drove across the median and into the northbound lanes, where it was struck head-on by a semitrailer, which was not able to avoid the crash, an Indiana State Police spokesman said.

McRae died at the scene of blunt force trauma, police said. Lewis Corron, 35, of Chesapeake, Va., a passenger in the SUV, also died at the scene of blunt force trauma.

A Lake County coroner's spokesman said McRae is a former resident of Crestwood, Ill., in Chicago's southwest suburbs.

The driver of the semi, John Taylor Jr., 54, of Greenwood, Ill., was not injured.

The truck was hauling a load of 11 cylinders of compressed chlorine gas, which stayed intact in the crash.

The crash closed various lanes in both directions between Lowell and DeMotte until nearly 2 p.m., when all lanes reopened.

Within minutes of the I-65 crash, two men were injured when they stepped out of their vehicles after a collision on U.S. 41 in southern Lake County and were struck by a third car.

One of the men was run over by a fourth vehicle.

Police said Bernard Scheidt, of Lake Village, was driving a semi northbound on U.S. 41 when he slowed for traffic at 141st Avenue about 5:30 a.m.

A car driven by Pete Doukas, of Lowell, struck the rear of the trailer, Lake County Sheriff's Department spokesman Michael Higgins said.

Scheidt and Doukas got out of their vehicles and were struck by a car driven by Charlotte Burns, 53, of Lake Village, Higgins said.

The impact sent the men flying in different directions.

A car driven by Brett Markusic ran over Doukas, struck Doukas's car and then crashed into the semi, Higgins said.

Scheidt and Doukas were admitted to a nearby hospital. Burns was treated and released. Markusic was not injured.

Hours later in LaPorte County, a father and daughter on their way to Blue Chip Casino were killed along with another driver after an accident just after 9 a.m. on U.S. 35 in Kingsbury.

Lloyd Klein, 63, was behind the wheel and his daughter, Amy Klein, 38, was in the front passenger seat of the SUV when a southbound car veered across the median into their path, LaPorte County Sheriff Mike Mollenhauer said.

Both the Kleins, along with Lloyd's wife and Amy's mother, Kathy Klein, who was riding in the back seat, are from Columbia City, Ind.

Kathy Klein was badly hurt.

The driver of the southbound car, Billy Hamblin, 72, of Kingsford Heights, Ind., was pronounced dead at the scene, LaPorte County Coroner John Sullivan said. Amy Klein also was pronounced dead at the scene.

Lloyd Klein was taken by ambulance to LaPorte Hospital in critical condition and was pronounced dead shortly before noon.

Kathy Klein was taken by ambulance to LaPorte Hospital in critical condition and later airlifted to Memorial Hospital in South Bend. Her condition was not known Tuesday evening.

All four persons were wearing seat belts, and airbags deployed in both vehicles, Sullivan said, but the safety devices were not enough to save all of their lives.

All four had to be extricated by firefighters.

Times staff writer Lauri Harvey Keagle and correspondent Stan Maddux contributed to the report.