While waiting every weekday for the No. 44 bus, Brian Mohr has watched his bus stop gradually become part of the most heavily guarded city block in the nation.
"First, they put all concrete carriers up, then they welded the manholes shut, then they took away the newspaper boxes, then they bolted netting on all the gutters," he said, surveying Stout Street in front of the federal courthouse where Timothy McVeigh's trial is taking place.
In an urban landscape peopled by U.S. marshals wearing bulletproof vests under suits, by Denver police officers mounted on horses, and by carloads of Federal Protective Service deputies repeatedly cruising by, the ponytailed dispatcher mused, "Maybe I'm increasing my chances of being blown up by standing here."
Denver, already edgy from hosting Oklahoma's bombing trial, was a bit edgier Friday as a series of events converged on Colorado just before April 19, the second anniversary of the bomb that killed 168 people, and the fourth anniversary of the fire at the Branch Davidian compound in Waco, Texas, which left 81 dead.
Just over two weeks ago, an Air Force A-10 Thunderbolt plane inexplicably veered from a training mission near the Arizona-Mexico border. Loaded with four 500-pound bombs, the plane disappeared from radar about 90 miles west of Denver.
On Tuesday, a "security threat" prompted the Air Force to install concrete barriers and suspend public tours at the North American Aerospace Defense Command, a radar center buried inside Cheyenne Mountain, 65 miles south of here.
The two events are unrelated to the Oklahoma bombing case and to the twin anniversary, the chairman of the Joint Chiefs of Staff assured the public Thursday.
But, in Denver, many people say the events seem strangely coincidental.
"Yesterday, all the kids were saying, "The A-10 is going to come back on Saturday and bomb Denver,'
" Khalil Kingsbury, a tourist from Iowa, said of a Little League baseball practice he attended.
Down the block, similar views came from Ron Cole. He was handing out flyers announcing the formation today of the "North American Liberation Army."
"Everybody in the militia movement is afraid that the A-10 is going to show up and bomb something," said Cole, whose leaflets were stamped with crossed automatic weapons. "Then, they are going to blame it on us, just like the Oklahoma bombing."
While police officers and marshals stood on three corners of an intersection, Cole stood on the fourth, distributing his flyers.
And while some celebrate today as Earth Day, others revere it as "Patriot's Day," the anniversary of the Revolutionary War battles of Lexington and Concord.
"We remember April 19 as the day that 86 of our friends and our brethren died," said Cole, citing a figure slightly above the official death toll.
This meaning of April 19 resonated at this corner, one of the most videotaped stretches of pavement on the planet.
Concrete barriers girdle the courthouse and the adjoining federal building, which includes offices for the FBI and the Bureau of Alcohol, Tobacco and Firearms.
In the steel-and-glass office high-rises that loom around the four-story courthouse, tenants have been drilled on how to handle telephoned bomb threats and on how to identify package bombs.
Polly Baca, a General Services Administration regional official, said: "We're blessed that April 19 falls on a Saturday this year. Your normal federal employee doesn't work on a Saturday."