Two Casper residents died Saturday in separate rollover car crashes in Natrona and Fremont counties.

A Shoshoni woman was also killed in the Fremont County crash and alcohol is being investigated as a possible factor in the wreck, according to the Wyoming Highway Patrol.

The first crash happened at about 3 a.m. when a Mercury Grand Marquis driven by Richard Baker, 49, rolled along state Highway 220, 27 miles south of Casper.

Baker was driving east when his car drifted off the south side of the road and struck a guard rail, the highway patrol said. The Mercury then veered back across both lanes of the highway and struck the opposite guard rail. It traveled up and over that guard rail, then rolled.

Baker, who was not wearing a seat belt, was thrown from the vehicle. He died at the scene.

The second crash happened four miles west of Shoshoni just before 10 p.m. Richard Tucker, 45, was driving south on state Highway 789 when his Dodge Dakota truck went off the right side of the road, according to the highway patrol.

Tucker overcorrected when he steered the pickup back to the left, which caused the vehicle to slide and then roll multiple times.

Killed in the crash were Zate L. Phillips, 28, of Casper, and Koleen G. Phillips, 51, of Shoshoni. Neither was wearing a seat belt, authorities said. Both died at the scene.

Troopers say they are investigating excessive speed and possible alcohol use as contributing factors in the crash. When they are finished, the crash information will be turned over to the Fremont Count Attorney's Office for review and any filing of criminal charges.