“Are You an Urban Adventurer? Spelunk bridges, explore tunnels,” read the advertisement in my neighborhood newspaper.

Two weeks later, I was crossing the Chicago River on the LaSalle Street bridge in the middle of the night with Keith Alexander and Mark Allgeier. Not on top of the bridge, but clinging to a rusted metal beam underneath it.

I’d crossed the LaSalle Street bridge hundreds of times, and it had never taken more than a minute or two. That Tuesday night it took more than two hours–two hours of inching my body along, hand over hand, grabbing footholds on the bottom of the girders and hoping not to fall into the river that lapped 70 or so feet below.

The underside of the LaSalle Street bridge consists of girders that arch over the river–first angling up, then leveling off, then sloping down on the far side of the river. There are eight 25-foot main girders, all about six inches wide. These girders are intersected by supporting girders with two-foot, egg-shaped holes cut in them.

It is these holes that allow you to climb from one girder to the next. Keith and Mark used a variety of techniques to get through the holes: feet first, head first, and sometimes behind first. I just crawled along like a worm.

Some of the girders are slightly offset, so that while you slither through one hole, you also have to twist your body to grab and pull yourself onto the next one. Halfway across, four girders north, we stopped. Above me, the infrastructure of the bridge stood out like a spiderweb against the night. There was the flash of the underside of a car, and I felt the vibration as it sped over my head. I could feel the middle of the bridge, where it opens, sag under the weight of a bus.

The second half of the bridge was more difficult than the first. My feet slipped on the dirt and on the inch-wide rust holes in the girders.

The girders sloped down, making it more difficult to cross from one to the next. I was filthy, cut and bruised, and covered with sweat. I made a last-second catch as my glasses slipped from my face.

I imagined being discovered and ending up in a jail cell somewhere. Keith and Mark had reassured me that they were not vandals and did these climbs for the sheer joy of doing them; I wasn’t certain the police would agree.

The hardest part of the crossing was getting back onto the sidewalk. We had to crawl through a tight, metal-lattice tunnel about 25 feet high and two feet wide. This tunnel, which probably has no function other than decoration, rises about 15 feet above the sidewalk, forcing us to climb up before we could come back down.

Halfway up the tunnel, claustrophobia took hold; I spent the next 20 minutes sweating, swearing, and gasping for air.

Finally, I made it to the top. Exhausted, dripping with sweat, I lowered my head and threw up. Slowly, I made my way to the safety of the sidewalk.

Art accompanying story in printed newspaper (not available in this archive): photo/Bruce Powell.