The World Happens to be Ending

We only made it two blocks before meeting someone. Thankfully, people's natural fear of firearms made them horrible shots. We heard the shot and a chunk of pavement exploded to our side.
"Shit!" yelled Kate, tackling me into an alley. We hit the ground with a crunch. The others ducked and followed us.
"Why did someone shoot at us?" Angie asked with wide eyes.
"Uh, guys. Look at us," said Kate.
She was right. We were generally somewhat disheveled, the females being a bit more refined. I suppose it made sense that someone would shoot at us.
"Hey there!" Willy yelled. "How about not fucking shooting at us!"
A pause. "How do I know you ain't them zombie things?"
Willy took a deep breath. "Because, if I remember my horror movies, zombies don't speak in educated discourse, if at all!"
Another pause. "Aright, that works for me. But, if you try to bite me, I'm going to shoot the shit out of you!"
Willy responded. "You have a deal!"
We stepped out and saw our wheelchair-bound apartment mate holding a rather large revolver. "I only missed 'cause I sneezed. Y'all are damn lucky!"
"What is happening out here? Where is everyone?" I asked
"Have you been under a goddamn rock? Not only did they send out messages in every media outlet, but they sent out Humvees with loudspeakers, telling everyone to take cover and lock their doors!"
"Really?" Willy said. "We were, um, drinking and playing video games. Come to think of it, it was kind of loud."
"So you didn't hear about the Hell Virus? At all?"
Angie spoke up. "Well, actually, Willy here invented..."
Willy interjected. "Ha, we saw a few reports. I thought it was, you know, those dirty terrorists or something."
"Yeah. Fuckin' Haji probably is behind th.."
Before his sentence completed, a man landed on his wheelchair, having jumped from a window above us. The man righted himself, thumping Johnny with an obviously-shattered arm, while biting on his neck."
"Shit! Fuck! Shit!" Johnny yelled.
I pulled my 9mm and and tried to get a bead on the man's head. It was difficult, since the man kept biting and yanking back. Eventually, after a series of bite, pull, bite, pull, I pulled the trigger.
BLAM!
The guy's head jerked back with a spray of blood, bone, and some more blood.
Willy's eyes were wide. "Dude! You fucking shot that guy! In the fucking head! That was awesome!!!" He stared for a few seconds and said "I think I need a gun."
"Yeah, if we find one. Oh wait! Look!" Johnny threw the corpse off of him and stood, an impressive task, considering he was in the wheelchair since the 70's.
"AAAAAHHHH!!!" Johnny yelled, as he limped towards us with bloodshot eyes. I mean, they were really bloodshot, like all the white was replaced with red.
I took aim just as Kate ran forwards with a battle-cry that would have made the Spartans crap themselves.
I had always thought that the canned, tinny noise of a movie sword was unrealistic. I was right.
Thunk.
Johnny's head spun off and landed in his wheelchair, where it stayed, working its jaws for a few seconds before it stared blankly forward.
Kate was grinning like a kid finding a five-dollar bill in her nostril. "Holy cow! This sword is awesome!"
We stared for a few seconds before Willy jumped towards Johnny's lower half. "Hey, I found a gun!"