A veteran firefighter responding to a one-car rollover accident on Interstate 5 early Sunday was critically injured when another vehicle skidded out of control and struck him.

Wynn Loiland joined South King Fire & Rescue more than 30 years ago with about 15 other firefighters, and together they watched their kids grow up.

The veteran firefighter was just two hours from finishing his shift early Sunday when he was struck by a car on Interstate 5 in Federal Way. Loiland and two other firefighters were on the shoulder, responding to a call about a rolled-over pickup. They found it abandoned.

Loiland, a 52-year-old Gig Harbor resident with a wife and two sons, was taken to Harborview Medical Center in Seattle with severe head and facial injuries, a collapsed lung and broken arm, said Deputy Chief Gordie Olson of South King Fire & Rescue.

“This is the most serious injury that we’ve had happen to any of our firefighters,” Olson said.

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Loiland’s family was keeping a vigil at the hospital, where his condition was listed as critical but stable. Some of his firefighter colleagues went to Harborview to offer the family support.

“Right now everybody is doing anything they can to help,” Olson said. “He was always the guy who’d come out and help you work on your house.”

The accident happened just before 5:30 a.m. Sunday, minutes after South King Fire & Rescue arrived in response to an earlier rollover accident.

According to the Washington State Patrol, a black pickup traveling south on I-5 hit the left barrier and rolled over at about 5 a.m., coming to rest in the right shoulder of the southbound lanes.

South King Fire & Rescue dispatched an engine, which Loiland drove. The roads were treacherous Sunday morning.

“It was a little bit icy and foggy,” Olson said. “It was even hard to see the vehicle that they were looking for. They didn’t see it until they were right next to it.”

The engine arrived on the scene at 5:21 a.m., about a half-mile south of the South 272nd Street onramp, where Military Road South runs under the freeway.

The crew got out and was standing next to the pickup, trying to see if anyone was inside. No one was, as the driver and passenger apparently had left, according to the State Patrol.

Meanwhile, Mario Jimenez-Perez, a 26-year-old Burien resident, was driving his red Chevrolet Blazer southbound at 5:28 a.m., when the Blazer skidded out of control and into the shoulder, striking Loiland and narrowly missing another firefighter and a lieutenant, Olson said.

Julie Startup, a Patrol spokeswoman, said slick roads and fog were factors in the collision. The investigation is ongoing.

The Patrol said it closed the two right southbound lanes from 5:45 a.m. until 9:45 a.m. Sunday.

Sanjay Bhatt: 206-464-3103 or sbhatt@seattletimes.com