As with some insoluble sports arguments, there are no easy answers in the 1947 accident that killed Eagles Hall of Famer Bill Hewitt.

No other vehicles were involved when his car ran off Route 309 near Sellersville in Bucks County and slammed into a concrete culvert. There were no indications he'd been speeding or drinking. And the roadway, while dampened by a light January mist, was hardly slippery.

Though authorities eventually speculated that Hewitt probably had fallen asleep, some now, in this age of CTE awareness, wonder if head injuries could have played a role in the death of the 37-year-old, two-way end who spurned helmets long after they became standard football equipment.

The issue of brain damage – especially among hard-hitting defenders like Hewitt and Brian Dawkins, the Eagles' latest Hall of Famer  – hangs over the game like a dark cloud. Was Hewitt, who played and died decades before concerns about the long-term harm of concussions, an early victim?

"From my point of view, it's a great mystery," said Upton Bell, who presented the deceased Eagles star for induction at Canton during Hall of Fame weekend in 1971. "Did this person who played so long without a helmet die from that? Or did he fall asleep?"

In a 1940 interview with Inquirer columnist Cy Peterman, just months after his surprise retirement at age 30,  Hewitt hinted at lingering head problems:

"`They knocked sentiment out of me early in the game. Knocked some other things out of here too,' tapping his shaggy cranium. `Would you believe I used to quote poetry by the yard? … But they beat me down to the average 12-year-old's IQ in a hurry.'"

When he was elected to the Hall, Hewitt had been dead 24 years. Since his 1971 class also included Jim Brown, Vince Lombardi, Y.A. Tittle, and Norm Van Brocklin, he was something of an afterthought at Canton. His daughter, Mary Ellen Cocozza, accepted his commemorative bust. But it was Bell's introduction that grabbed the attention of an audience that included President Richard Nixon.

Hewitt was not just a sure-handed receiver and a ferocious hitter, Bell told the crowd, but he did it all with no protection on his head. The 5-foot-9, 190-pounder was the last NFL player to perform without a helmet, spurning one until his final Eagles season, 1939, when the league finally made the headgear mandatory.

"I remember the people in the audience murmuring, almost gasping, when I mentioned that," said Bell, 80, the retired Patriots general manager and Boston talk-show host who lives in Cambridge, Mass. "I was sitting next to President Nixon and when I got back to my chair, he said, `He really played without a helmet?'"

Hewitt had won two NFL championships with the Bears and was a three-time first-team all-pro when, for whatever reason at age 27, he threatened to retire before the 1937 season. Chicago owner George Halas traded him to Philadelphia, along with $4,000, in exchange for that year's No. 1 draft pick, which he used on Sam Francis.

"My suspicion, and I've talked to other people about it, is that he did [suffer from head injuries]," Bell said.  "The only reason my father picked him up was the $4,000. That was like $100,000 today."

There was no letdown in his play. In all three of his Eagles seasons, Hewitt again was named first-team all-pro. He caught a career-high 18 passes in 1938 and was a demon on defense. The Bears would retire his No. 56, and in 1987 the Eagles installed him in their Hall of Fame.

He was a quality pass-catcher in a run-dominated era and a fierce defender with unusual quickness. His defensive anticipation was so keen that some called him "The Offsides Kid."

Just 2 when Hewitt retired – he returned briefly in 1943 to play with the Steagles, a wartime combination of the Philadelphia and Pittsburgh franchises —  Bell never saw him in person. But the way his father, Bert,  and others described his tackling, "made me glad I wasn't on the other end."

"He was a great player and probably a better defensive player," said Bell. "He wasn't a real big guy, but he could break your neck. But I was surprised a little when he got [elected to the Hall]. The process is probably different now and I'm not sure he'd get in."

According to Bell, the lantern-jawed Hewitt also was "one of the strangest people who ever played for my father."

"He was a distant guy and some people described him as being not all there," Bell said.

Bell toured NFL training camps with his father, by then the league's commissioner, in the 1940s.  He said many of the players he saw and talked with had suffered head injuries.

"They wouldn't call it a `ding.' They'd say, `Gee, I felt really funny for a while.' And  a guy like Hewitt who played hard and played without a helmet would have to have had some concussions. Did they have long-term effects? Who knows?"

After retiring in 1939, Hewitt worked for the Supplee-Wills-Jones milk company and lived in Drexel Hill. His name disappeared from the newspapers almost immediately. It would resurface tragically on Jan. 15, 1947, the day after his fatal accident.

"Of all the players I can think of," said Bell, "he's the one guy that I can say to you no one really knew much about. There was just this mystery around him. A mystery that even extended to his death."