Science teacher Tim Turk is the kind of fellow who tends to see his beaker as half-full. It's a good trait for someone recovering from 10 broken bones and a traumatic brain injury.

Science teacher Tim Turk is the kind of fellow who tends to see his beaker as half-full. It's a good trait for someone recovering from 10 broken bones and a traumatic brain injury.

"I'm here. I'm breathing. And I keep getting better every day," Turk said.

Turk, 46, spun his wheelchair in a half-donut Friday afternoon, then jetted down the aisle of his classroom at McLoughlin Middle School. One foot propelled the chair, and one hand waved a pink sheet bearing the periodic table.

"The students have been an amazing support for me," Turk said. "Sometimes I stop in the middle of a story because I lose track of where I am, or I'm searching for a word. And they supply it. Then I've learned it again, and I have it again."

Turk was finishing up a bike ride with several buddies in the San Francisco Bay Area one weekend in May, about three weeks before the end of the school year, when he collided with a speeding motorcycle rider.

Turk doesn't remember the accident. In fact, he doesn't remember much of anything from then until a week later.

But witnesses have told him that he turned left in front of the motorcycle.

Both riders tried to avoid each other, but the crash was horrific. The motorcycle rider somehow managed to escape serious injury. Turk was not so fortunate.

"I broke 10 bones, smashed my pelvis and I broke my helmet," Turk said. "Yes, I suffered a traumatic brain injury. But just think what would have happened if I hadn't been wearing my helmet."

Janet Turk detailed her husband's injuries, and the anxious hours she and family and friends spent at his bedside once she got the call on May 18.

"I didn't know the extent of things until I got there," she said.

Both Tim and Janet Turk know they are fortunate he didn't suffer spinal cord or organ injuries and that his brain injury was not more significant.

"He had no personality changes. His attitude has been super-positive. And his short-term memory has improved," she said. "It's not obvious to me anymore."

A community of friends rallied around while Turk endured stints in three separate Bay Area hospitals, a couple of surgeries and several months of rehabilitation therapies.

"We never left him alone," Janet Turk said.

Supporters rallied by setting up meal trains, organizing fundraisers to help with expenses and other kindnesses throughout the entire summer, she said.

"It was really phenomenal," she said. "It really does make a difference to people when something like this happens."

The start of the school year saw the 14-year-veteran teacher back in the classroom — a walking, talking, life-size science experiment in physics and physiology for his students.

"My first day back I told them what happened to me. I showed them my X-rays," Turk said.

Turk pulled out a "normal" skeletal system and compared it with his own, which includes several bones bearing large fractures knitted together with titanium pins.

The students say they're thrilled to have their favorite teacher back in class. They also appreciate his real-life lessons.

"There were long metal screws that were like 5 inches long," said 14-year-old Karen Valle.

Karen said Turk has shown considerable improvement since school started in September.

"He knows how to explain things really well," Karen said. "He's really fun."

Science is MacKenzie Radillo's favorite subject. The 13-year-old said she is happy to have Turk back, and "acting normal."

Turk is happy to be back in class, too. But he's also still attending weekly physical and cognitive therapy sessions, he said.

"They call it speech therapy. But it's really about cognitive development for my short-term memory issues," Turk said.

In addition to breaking his shoulder, several ribs, puncturing a lung and shattering his pelvis, Turk suffered a small brain bleed during the accident. The brain injury has resulted in some short-term memory issues that make it more difficult for him to remember names.

Sometimes he needs a little nudge to get back on track when he's relating a story on, say, the theory of relativity, he said.

"Big science-y words are hard for me," Turk said with a chuckle.

McLoughlin Principal Linda White watched while Turk stood and limped to the front of the class with the aid of his cane. Once there, he informed his students that sodium, an explosive metal, and chlorine, a lethal gas, combine to form something that ends up getting sprinkled over french fries.

"You call it salt," Turk said. "I just love that."

White smiled as Turk sank back into his wheelchair with a quiet grunt. Within seconds, he was rolling down the aisle to help a student.

"He still seems to know his sciences," White said.

Reach reporter Sanne Specht at 541-776-4497 or e-mail