Editor's Note: This article is part of a series that looks at the top 10 traits exemplified by Inc. 500 entrepreneurs. 

Gallup says people with determination have tremendous work ethics, confront and overcome obstacles, and are undeterred by failures or roadblocks.

At 6:30 a.m. on May 21, 2011, Bernadette Coleman was awakened by the kind of phone call every parent dreads. There had been a car crash. Her son, Michael, had been thrown 40 feet in the air and landed on his head. He was in a coma.

Coleman and her husband, Tom Coleman, flew immediately to Florida, where Michael, 26, hovered between life and death. They left behind their company, Advice Interactive Group, based in McKinney, Texas. The company, which provides digital marketing services to small businesses, was in its second year and just beginning to find its sea legs. Coleman was CEO; her husband, CFO. With both absent, the business was essentially leaderless.

With personal tragedy looming, that was the least of the Colemans' concerns. On the third day, a doctor suggested they consider removing the machines keeping Michael alive. The couple refused, keeping vigil in the ICU for 30 days and then, when Michael finally awoke, sticking by him as he moved into the general patient population.

"During that entire time, we were running the company from a laptop by his bedside," says Coleman. "I can't tell you how many phone calls I had to take out in the hallway. I'm a loud speaker, so I had to learn to speak quietly on the phone. In the hospital, I got shushed a lot.

"I spent a lot of time in the stairwell," Coleman continues. "I'd pull a chair in there and sit with my laptop and my phone and my briefcase. For the doctors and nurses coming up and down, it was a running joke that that was my office."

Back at the real office, things were going badly. Rumors circulated that, with both founders absent and distracted, the company wouldn't survive. Within a few weeks, half the staff had quit--including a contingent that tried to start a rival company and poach some of Advice Interactive's clients. "From that experience, we learned that while you want to run a business like a family, it's still a business, so you have to paper up," says Coleman. Starting in the second month of Michael's hospitalization, the Colemans took turns flying back to Texas to hire replacements.

Advice Interactive's salespeople continued to sell; but without the Colemans' leadership and subject-matter expertise, projects were delayed or done incorrectly. The Colemans doubled down, working in the hospital by day and then well into the night to correct the problems themselves. In a few cases, they were forced to recommend that clients find alternatives. "We would never take a chance on doing something detrimental to our clients' businesses," says Coleman.

Altogether, Michael spent six months in hospitals in Florida and Texas, and then another six weeks in a nursing home. Even after he was discharged, his parents spent considerable time driving him to rehab appointments or to additional operations. But Coleman says they never considered temporarily shrinking the business. "We couldn't do that," she says. "Our goal was still to help as many small businesses as we could."

Michael, who suffered a traumatic brain injury, now lives at home, although he is largely able to care for himself. With the Colemans back in charge, Advice Interactive quickly regained momentum. This is the company's third year on the Inc. 500.

"We were fighting for our son's life and for the company," says Coleman. "We had no choice but to prevail at both."