The dead take no selfies.

So there might well never have been the remarkable selfie that 16-year-old Nate Scimio took after his heroism at Franklin Regional High School if he had faced a gun rather than two knives on Wednesday morning.

In all, Scimio and 19 other students, along with one staff member, were stabbed when a sophomore allegedly stormed through the school in Murrysville, Pennsylvania. Three students were critically injured.

One, a girl, was saved from bleeding to death when a classmate kept paper towels pressed against her wound. Another, a 17-year-old boy, was stabbed with such savagery that the wound in his abdomen was 2 inches wide and extended almost to his spine. The blade pierced his liver and diaphragm, missing his heart and aorta by a fraction of an inch. He was on life support after emergency surgery, but doctors remained hopeful he would survive.

And, as of the end of the day, none of the 21 victims had died. Scimio had managed to escape serious injury even as he shielded several students from the attacker and took a moment to pull a fire alarm to alert everyone else. A fellow student named Trinity McCool credited him on Twitter with saving her and a friend.

“Without Nate, me and Lindsay would’ve been injured and there’s not enough words to describe how much of a hero he is,” McCool tweeted.

Scimio survived to take a picture of himself in Children’s Hospital. The photo that might never have been shows him holding up his camera with his right hand while he points with his left to the bandaged wound on his right forearm.

“Chillin’ at Childrens,” he captioned the selfie he posted on Instagram.

Scimio most likely had instinctively thrown up that now wounded arm to ward off the attacker’s blade. The impulse would have done nothing to deflect a bullet, which would likely have torn through his arm and into him. He then might have been quite literally chillin’ at the morgue.

Instead of posing for a selfie with a half-smile in a hospital gown, Scimio and who knows how many of his classmates might very well have been as dead as the three soldiers who were mourned by President Obama on Wednesday in the aftermath of the latest mass shooting at Fort Hood. Obama attended a similar ceremony at the base five years ago, after a previous mass shooting left 13 soldiers dead.

Obama might even now be planning a trip to a memorial in this small Pennsylvania town 20 miles east of Pittsburgh if the mayhem at Franklin High had been perpetrated with a 9-mm pistol like the one the 2009 Fort Hood gunman used or the .45 caliber pistol the more recent shooter wielded.

Had there been a gun at Franklin High, the dead might very well have included the school safety guard known to the students as Sarge, who was stabbed in the stomach while trying to stop the attack. The very brave vice principal, Sam King, who then jumped in, might have been killed before he subdued the 16-year-old suspect.

Afterward, the suspect was placed in the back of a marked police car. He sat with his head bowed, as blank-faced as he is said to have been through the whole attack. He looked impossibly young, too small and scrawny to have done much harm without some kind of weapon in a school that boasts a great wrestling team.

Authorities identified the suspect as 16-year-old Alex Hibbal. He is said by police to have begun his rampage just after 7 a.m., when he allegedly burst into a classroom in the science wing brandishing two large butcher knives. Police say he continued to stab and slash as he returned to the hallway, causing other students to stampede away from him.

“Go to your cars! Go to your cars! Someone is stabbing people!’” a voice cried out.

Nobody could have outrun a bullet if the suspect had been armed with a gun, but anybody who managed to stay outside the reach of the blades escaped injury. One unlucky boy who was stabbed in the back reportedly was comforted by 16-year-old Kristen Beard, who remained at his side and made him a promise.

“We’re going to go to prom and have so much fun and you’re going to be OK,” Beard told her friend, according to NBCNews.com.

At least one student, 18-year-old Ian Griffith, is said to have assisted the vice principal in subduing the suspect and ending the carnage. Griffith, Scimio, and Beard would all seem to be good candidates for a scholarship awarded in honor of Frank Miller of Franklin Regional’s class of 1986, who went on to become a police officer of noted bravery and was shot to death in the line of duty, his bulletproof vest having proved no defense against a bullet to the head.

The mass stabbing suspect is said to be a neighbor of the vice principal and is described as quiet, shy, and a bit of a loner, but not friendless. He is said to like finding funny photos on Facebook. There were no early reports of him having been bullied. He is expected to be charged with attempted murder unless one of the most seriously injured victims takes an unexpected turn for the worse. The “attempted” would then be dropped.

The motive at this point officially remains a mystery.

“Initially, we don’t know what led up to this,” said Murrysville police Chief Thomas Seefeld.

Until Wednesday, the closest this high school of 1,200 students ever came to such an incident was in September 2009, when an email that appeared to have been sent by a ninth-grader threatened a gun attack. Police put the school in lockdown and searched the classrooms and lockers, with no result. It was later determined that somebody had hacked the student’s email account via a server in the Czech Republic.

At least when an all-too-real attack came on Wednesday morning, there was only the flashing of blades, not the roar of gunfire. The knives were enough to turn the school into what the police chief described as “a vast crime scene” and to force the cancellation of a lunchtime preview of the prom DJ. The prom itself is scheduled for Saturday and may well be postponed, but maybe Beard’s wounded friend will be well enough by then for her to make good on her promise to take him.

And, if the doctors’ expectations hold, everybody will survive along with Scimio to keep taking selfies.