A masked man burst into a 7-Eleven near Seattle early Sunday morning, swinging a hatchet and slicing the store clerk.

Before the masked man could seriously hurt anyone, though, a customer who was drinking his morning coffee pulled out a concealed weapon and fatally shot the attacker.

Authorities did not name the attacker or the customer, but they did hail the concealed weapon owner as a hero.

“This could have been disastrous,” King County Sheriff Sgt. Cindi West told KIRO7. “Had this guy not shot, who knows what would have happened? We might have a dead clerk right now, and instead we have a dead bad guy.”

The clerk, Kuldeep Singh, suffered minor cuts to his stomach. He, too, thanked the customer for saving his life.

“He [was] killing me,” Singh, 58, said of the hatchet-wielding attacker. Singh added that the customer was a “nice guy.”

West said that the incident will be investigated fully but that the 60-year-old customer was currently being considered a Good Samaritan.

The “customer, the shooter, is shaken up but from everything that we see right now from the scene – there’s no wrongdoing on his part,” she told King 5. “In fact, he probably saved a life in this case.”

The incident near Burien, Wash., about eight miles south of downtown Seattle, probably will add to the ongoing debate about concealed weapons and their effect on crime.

Concealed-weapon ownership has skyrocketed in recent years as more states have moved to allow it. The percentage of Americans who believe owning a gun will protect them and others also has risen steadily.

There is little consensus on the efficacy of concealed weapons in reducing crime, however. Although supporters of concealed-weapon ownership argue that it discourages crime, some studies have shown it has no effect. Other studies have found it actually increases crime.

Anecdotal evidence abounds on both sides of the argument.

In January, a man in Renton, Wash., just a few miles away from Burien, brought his concealed weapon into a movie theater. Dane Gallion was reportedly worried about public shootings. Instead of stopping one, however, he committed one, shooting a woman in the back in what his attorney later claimed was an accident. Gallion was arrested and charged with third-degree assault.

Similarly, a Michigan woman was charged with misdemeanor reckless use of a handgun after she shot at shoplifters fleeing a Home Depot in October. After she was sentenced to 18 months probation, Tatiana Duva-Rodriguez said she would “never help anybody again.”

Both individuals were stripped of their rights to carry concealed weapons.

In November, when a would-be robber burst into a Chicago bodega waving what looked like a handgun, a customer with a concealed weapon fatally shot the intruder, only for it to turn out that the robber’s gun was fake. In that case, the concealed-weapon owner was not punished.

But there are also instances in which concealed weapons appear to have saved innocent lives.

On Jan. 22, the day after the movie theater shooting, a pair of concealed-weapon permit-holders prevented what might have been a mass shooting in Columbia, S.C. When two armed men tried to knock over a barbershop, a pair of customers pulled out their weapons and opened fire, killing one and sending the other one scrambling. There were several children inside the barbershop at the time of the shooting, according to WISTV.

Sunday morning appears to have been another instance in which a bystander with a concealed weapon saved an innocent life, albeit by killing an attacker.

Wearing a baseball hat atop his curly white hair and mustache, the customer was sitting in his usual spot near the clerk’s counter, sipping his morning coffee, when the masked man burst into the 7-Eleven.

Without saying a word, the attacker slashed at the customer with his hatchet before turning toward the store clerk.

“The guy came in with a mask just swinging the hatchet at both of them,” West told King 5.

That’s when the customer drew his pistol and fatally shot the masked man.

The customer was too shaken to speak to media afterward, West said.

Meanwhile, the motive for the bizarre, early-morning attack may never be known. The masked attacker is believed to have been in his 40s, according to authorities. His identity will be released at a future date.

Clarification: The 7-Eleven is located outside of Burien city limits, although Burien Police responded to the incident, a city official said.

Read more:

Man who feared mass shootings brings gun to movie theater, accidentally shoots woman

Concealed gun permit holder fatally shoots suspected robber during Chicago stickup

‘Worst nightmare’: Woman with concealed gun permit shoots at fleeing shoplifter outside Home Depot

Mich. woman who shot at shoplifters gets 18 months probation, vows to ‘never help anybody again’