A Mendocino County woman who crashed after part of a brake assembly broke free from a big rig in front of her on Highway 101 likely died from injuries suffered when a large piece of wreckage struck her, the CHP said.

Investigators believe Sugey Garcia, 23, was hit by a piece of brake drum that flew through the windshield of her Subaru Impreza, CHP Officer Kylar Adams said Friday.

“This is a fairly large piece of metal, weighing 30 to 40 pounds, that struck the vehicle,” Adams said. “So it’s a fairly large piece of debris.”

Garcia was northbound on Highway 101, approaching the town of Willits, where she lived, when the brake assembly on the semitractor-trailer apparently blew apart just before noon Wednesday. The impact and injury caused Garcia’s car to careen across the southbound lanes and over a steep embankment on the west side of the highway, Adams said.

Her car came to a stop about 100 feet down the embankment, he said.

Garcia was being airlifted to Santa Rosa Memorial Hospital when the helicopter crew landed instead at Ukiah Valley Medical Center, where she was pronounced dead.

Autopsy results will not be available for several weeks, Mendocino County Sheriff’s Capt. Shannon Barney said.

Adams said the embankment down which Garcia’s Impreza crashed was steep, with several trees, but he said it did not appear the vehicle rolled.

Mendocino County Animal Control personnel said two dogs, an adult pit bull and a bull terrier puppy, survived the crash and were retrieved from the county shelter by family members Thursday.

Authorities are still trying to track down the big rig involved, saying it’s possible the driver didn’t stop because he or she was unaware of the damage to the rear trailer.

Witnesses have described the rig as a white, three-axle conventional style semitractor trailer, possibly a Volvo, hauling a dark, red-orange or rust-colored container trailer, possibly a Conex.

The truck likely would have wheel or brake drum damage on the trailer, as well.

Antonio Munoz, owner and head coach at CrossFit Mendocino in Ukiah, where Garcia had been a member for about six months, said she had been embraced by the gym community and had been encouraging friends and family members to join and improve their physical condition.

“She was just a very kind, gentle soul that treated everybody with respect and kindness, no matter what you looked like or how much money you had or what you drove,” Munoz said through tears. “She’s going to be deeply missed.”

Anyone with possible information about the incident is urged to call the CHP Ukiah Area Dispatch Center at 707-467-4000.

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.