About 4:30 p.m. Saturday, Dec. 17, he was working in his shop on a wooden display frame for six decorative puzzles. He was making a slot for a plexiglass cover when the saw blade kicked.
The blade chewed into his left hand, breaking three fingers, lacerating the back of his hand and all the fingers. He lost the tip of his middle finger. His ring finger was ripped open.
Everyone needs a functioning left hand, but Ferguson's passions in life all depend on that hand. He plays upright bass for Marshall Philharmonic Orchestra. He plays tuba for Marshall Municipal Band. He teaches music at Missouri Valley College. He teaches private music lessons on various instruments. He makes quilts. And he is a woodworker.
"I was fortunate" was Ferguson's second observation when talking about the accident recently. When he saw his hand after the run-in with the saw, he said he was relieved to see that everything was still attached. It could have been worse, he said.
His first observation: "It was foolish."
Ferguson is not new to woodworking. His father was a professional carpenter. He grew up around woodworking and knows safe practices and the possible consequences of taking shortcuts.
He remembers working at his father's job sites when he was young.
He heeded the lessons from those carpenters -- except this time.
"I knew I shouldn't push that piece the other way," he said. "I just didn't think long enough. It wouldn't have taken another 10 minutes to do it right."
His brother, John, a professional electrician, who was visiting the Fergusons, added a caution. Charles' ring finger suffered the worst damage because he was still wearing a ring.
"Anyone doing mechanical work should take off all jewelry," he said. "That's what we were taught as apprentices."
"And he still has all his parts and pieces," Charles added.
Ferguson hopes others who work with machinery will learn from his experience.
A momentary lapse in safe practices can result in an accident, even for experienced, safety-conscious workers.
"There's always potential of bad things happening," he said.
It's better to take the time to do things properly, he said.
The accident is a serious setback to pursuing his various passions, but the prognosis for regaining full or nearly full use of his hand is good, he said.
His wife, Norma Jeane Ferguson, also a bass player and quilt maker, said the local emergency response and Columbia health care systems played a big role in saving Charles' hand.
She said Marshall police and Saline County Ambulance crews responded quickly. An Air Evac helicopter was available and wisked them to a Columbia hospital, where Charles' hand was tended by emergency room doctors.
Sunday, Dec. 18, he underwent surgery.
The surgeon was Dr. Mohamed Khalid, a hand and wrist specialist, and his assistant was Dr. Kevin Paisley, who happens to be a bass player himself.
Norma Jeane said the surgeons knew Charles was a musician and took care to place remaining nerves so he would regain enough feeling in his finger tips to be able to play again.
Charles also said he was lucky the first, middle and pinky fingers were damaged less than the ring finger, because those fingers are more important when playing the upright bass.
Norma Jeane said Charles is eager to begin rehabilitation work and is prepared for what it will probably involve.
He said he knew a concert violinist when he was in college who had suffered a dog bite on a finger when she was young.
"She was always flicking that finger to keep it flexible," he said. "I've got something a little more comprehensive, (but) use is the best thing for any wound like this."
In a way, his long experience as a diabetic may have prepared him for what's ahead, he said.
"We're taking care of ourselves 90 percent of the time," he said. "You learn how to do it right. I'm interested to see what to do and start doing it."
He's hoping to regain enough strength and flexibility soon to return to the activities he loves: music, sewing and woodworking.