Thomas A. Kocon was driving with four girls piled in the back of a Dodge Durango and another girl in the passenger seat, but he allegedly refused to put the rear seats down to let everyone buckle up.

Prosecutors said yesterday that fatal results followed when Kocon added reckless speeding to the mix late Dec. 12. Authorities charged Kocon, a student at the Western Center for Technical Studies in Limerick, with two counts of homicide by vehicle, five counts of recklessly endangering other persons, and other offenses, including driving without insurance.

According to the Montgomery County District Attorney's Office:

Kocon, 18, was going about 20 miles per hour above the 55-m.p.h. limit on Route 100 in Upper Pottsgrove when the 2003 Durango swerved into a guardrail, rolled over, and slid on its roof at 11:49 p.m. Three of the girls in the back, including a 12-year-old riding on a 15-year-old's lap, were ejected during the wreck, in which the car skidded more than 300 feet.

Breanne Brothers, 15, and Andrea Antonio-Harris, 16, were killed. The 12-year-old and two 17-year-old girls were taken to hospitals, as was Kocon.

Kocon was arraigned yesterday in Pottstown before District Judge Thomas A. Palladino, who set bail at $50,000. Kocon was still in the Montgomery County Correctional Facility last night, according to jail records.

Reached at their Pottstown home, Kocon's family members declined comment.

The accident was among three fatal crashes involving teenagers over three weeks in Montgomery and Chester Counties.

On Nov. 23, two Pottsgrove High School students were killed in East Coventry, Chester County. The two were among six students in a Honda SUV that went out of control on Route 724.

Then, on Dec. 2, three teenagers from West Caln Township were involved in a two-vehicle collision. An 18-year-old was driving a Pontiac Sunfire east on West Kings Highway in West Caln when it crossed the center lane and collided head-on with a trash truck. His two passengers were pronounced dead at the scene.