DETROIT — Imagine firing up a chainsaw … next to a jet engine … in a one-car garage.

For much of Sunday, that’s about what it felt like to be at Ford Field on the loudest day of its football life.

Then …

Imagine sticking a box of thumbtacks into a beach ball.

That’s the hissing sound we heard at the end of the Lions’ 37-31 overtime loss to the Seahawks, the air coming out of the stadium.

“Appreciate our fans,” Lions coach Dan Campbell said. “They showed up and they did their part.”

Now, if only he could have done his.

Too harsh? Sorry, I don’t mean it to be.

I love Campbell, and applaud the remarkable job he’s done in transforming Detroit into a team as tough as it is fun.

And don’t think we’ve forgotten about the defense or the two turnovers that led to Seahawks touchdowns.

Both played big roles in this letdown. (Lions fans might throw the officials in there, too.)

But as the most anticipated Lions season in decades took an early detour, it’s impossible not to talk about the elephant in the stadium:

If these aren’t the Same Old Lions, they lost by falling into old habits, including Campbell’s bizarre whims.

How to explain his decision-making?

One moment, he’s Evel Knievel, daring as ever. The next, he’s more conservative than the Tea Party.

Consider two of the key judgments that swung the game.

Start with the Lions going for it on fourth-and-2 from their own 45, up 21-17 in the final minute of the third quarter.

Campbell’s fourth-down gambles are a big part of the Lions’ identity, and the analytics usually back him up, but there’s a fine line between bold and reckless, and he jumped over it here.

Offensive coordinator Ben Johnson — who otherwise called a good game — then dialed up a slow-developing play-action pass that resulted in an incompletion, and, moments later, a go-ahead Seattle touchdown.

You might say, fine, you win some bets, you lose some, and that’s fair.

But then how to explain his flip-flopping in the final minutes of the game?

Down a field goal, the Lions got the ball at the 50 with 1:44 left.

They had all three timeouts and — with Jared Goff dicing Seattle for 323 yards — an offense that was moving at will. The choice was clear: Floor it and go for the TD.

Instead, Campbell was way too content settling for the field goal, wasting 78 seconds on the first three plays of the drive — two of which produced first downs — before calling his first timeout with the Lions at the Seattle 27.

“I wanted to take it as it came,” Campbell said. “Here’s what I knew, they had two timeouts and I did not want to give that ball back, that was No. 1. No. 2, can we get down there far enough to score a touchdown? And so, I already had in my mind if we get it to a certain point on fourth down, we will go for it, if not we won’t, so kicked the field goal. I felt like our chances were really good in overtime and it didn’t work out.”

I get the thinking. I just don’t get, well, the thinking.

With the Lions’ rebuilt defense looking a lot like the unit that ranked 29th in total D last season — they got no heat on Geno Smith as the Seahawks passer completed 32 of 41 passes for 328 yards — Campbell wanted to leave the game to the whims of the overtime coin flip?

He wanted to risk leaving the game in the hands of the same D he showed no faith in on the earlier fourth-down gamble?

He did just that, the Seahawks won the coin toss, strolled down the field for the winning score, and the Lions (1-1) returned to earth.

Looking back, maybe we should have seen it coming.

On the Seahawks’ first must-convert play of the first drive of the day — just as the PA man roared, “Motown, it’s … THIRD DOWN!” and the roof was about to be blown into orbit — the Lions were whistled for having 12 men on the field.

First down, Seattle, and, before long, touchdown, Seattle.

For just a moment, the place went silent, as if mom and dad unexpectedly returned home in the middle of a big blowout.

It seemed like a false alarm.

In fact, that knock on the door? It was just the cool neighbor checking to see if the youngsters needed more ... sodas.

The Lions answered with a quick TD and the party raged on ... until it didn’t.

I’ve had the good fortune to be at more big events than I deserve, many charged with enough voltage to power a small town.

The World Series. NBA Finals. NFL playoff games. College national championship games. Ohio State-Michigan.

Crazy as it sounds, I’ve never heard a building louder than Ford Field was at its peak decibels Sunday.

Lions fans — their team fresh off a season-opening win over the defending Super Bowl champion Chiefs and the betting favorite to win their first division title in 30 years — are that excited about this season.

And, of course, they still should be.

So long as the Lions respond and take this tapping of the brakes as a reminder of what it takes to win in the NFL.

And, yes, that includes the guy in charge.

“I know it stings and those guys are disappointed,” Campbell said. “I’m disappointed, the staff is, but my gosh man, this is good. We’ll get a little humble pie here.”

First Published September 18, 2023, 12:29 a.m.