Fatal Crash Prompts Order for Wall on Simi Freeway Median : Northridge: A woman dies in a head-on accident along a stretch of roadway where several such deaths have occurred.

A Pacoima woman was killed and a West Hills woman was injured Monday when a car slid across the dirt median of the Simi Valley Freeway in Northridge and crashed head-on into oncoming traffic, bringing to six the number of people killed this year in similar accidents along that stretch of roadway.

Within hours of Monday’s crash, Caltrans officials ordered nearly five miles of concrete wall to be installed along the freeway as a temporary barrier to prevent cars from crossing the 43-foot-wide median strip.

Construction is expected to begin next Monday between Balboa Boulevard and DeSoto Street and should be completed by the end of the month, Caltrans spokeswoman Margie Tiritilli said. The barriers are a temporary measure until a more permanent wall can be installed early next year.

“We feel very distressed to hear there is another accident and another fatality,” Tiritilli said. “These shouldn’t be happening and we don’t know why they are. But we’ll do what we can to prevent any more.”

In Monday’s crash, Grasiela Castillo, 31, died after her car swerved across the westbound lanes of the freeway and the dirt median into eastbound traffic, clipping another car before slamming head-on into a van, California Highway Patrol Officer Susan Billat said. Another car rear-ended the van.

Investigators did not know what caused the driver to veer across the freeway.

Castillo died at the scene despite immediate medical attention from firefighters who witnessed the crash as they drove to a training session.

Los Angeles Fire Department engineer Ed Sandell said he was driving east on the freeway when he saw the woman’s car swerve across the median strip and into oncoming traffic. After the collision, Sandell and several other firefighters ran to the wreckage, but “she was hopelessly pinned in the car.”

The driver of the van, Peggy Cox, 43, of Canoga Park, suffered moderate injuries and was taken to Granada Hills Hospital, Billat said. Sandell said Cox may have avoided more serious injury because her car was equipped with an air bag.

“After I got everyone out, I noticed a perfect imprint of her lipstick on the air bag,” Sandell said.

The drivers of the other two cars were not hurt, Billat said.

Monday’s crash follows two similar accidents this year in which cars swerved across the median strip into opposing traffic. A total of five people were killed and six were injured in those accidents, prompting Caltrans officials to call for the construction of a median wall to prevent crossover collisions.

A construction contract for the five-mile wall was awarded in September, but the contractor has not yet finished casting the concrete walls. The temporary wall, ordered Monday from a freeway improvement project in San Diego, will be in place until the contractor finishes the more permanent barrier and installs it, Tiritilli said.