Big Boom, though not so near.
April 19, 1995, at about 9:00 am, I was driving south on the Hefner Parkway, five or six miles from the Alfred P. Murrah Federal Building, when Timothy McVeigh blew the place up. I drove into the pressure wave generated by the blast. At that distance, the blast front hit my car like an unusually strong gust of wind. WHOOM! and gone. Strange thing to run through on a bright, sunny morning, and being almost imperviously incurious while on my way to teach a bunch of English undergrads, I kept going.
Then I saw a column of white smoke rising above the city south and slightly east of my direction of travel. I thought, hey, grass fire. Then the dark smoke started. I thought, hmm, something else is burning. The smoke column simply grew and grew and went from white to very dark gray and black. I thought of all kinds of things. Train derailment fire. Toxic chemicals spilled from train on fire. Plane crash. Something serious, in any event. So I flicked on the radio. All local stations were intermittently running regular programming and a few news briefs about the explosion. As the scope of the explosion became increasingly apparent, all local programming simply turned to wild speculation about what had blown up, the most often-cited cause being “gas line.” Since nothing definitive was coming out of the radio, I turned it off and kept driving.
I was teaching at a local college then, and by the time I arrived (about another six miles south of the blast site), there was much chatter about the federal building having blown up, but no one knew why, yet. So off to class I went, and what a bizarre-o-world that turned into, what with one student plugged into her radio, a bunch of others fruitlessly trying to make phone calls, still no one knowing what had happened, but news leaking out from our plugged-in student indicated that almost half of the Alfred P. Murrah Federal building was gone and the blast site was a mess of wreckage, smoke, confusion, and rescuers.
Come to find out later, this blast was so powerful that folks in my neighborhood, eleven miles north of Oklahoma City, had all come out of their homes when the blast front swept over them, rattling walls and windows and dishes. To a man and woman and child, all thought that something heavy had hit their rooftops hard enough knock holes. Even the dogs didn't like it, all of them spooked and barking. Rooftops, however, remained intact.
Did the sky turn black? No. Did ash rain down? No, again, but a bunch of Ryder truck parts landed on rooftops and streets all around the blast site. Did the earth shake? Yeah. Twice. Once from the bomb. A second time from the building falling apart. Each of these seismic waves, ten seconds apart, were measured by two separate seismographs, one located about four miles away, another about sixteen miles away.
Is it the loudest sound imaginable?
Six miles away, in a car with the windows rolled up, I didn't hear anything more than a really loud gust of wind. Near enough to the site itself, I imagine it likely sounded like a pretty big boom, but the closest I've been to exploding things has been downrange during an artillery demonstration, and closer still to much smaller destructive devices. Much like firedrake's report, those sounds have been pretty unremarkable. The artillery shots on a vehicle group, using airburst shells of some sort, just made a loud BANG! with a small, unimpressive poof of smoke. The vehicles were riddled with holes, though.
It's helping me a lot with the description.
