Ten thousand pounds of groceries teetered over the bridge.
The 48-foot-long truck trailer had been ripped across the middle by the force of a collision and now lay on its side, protruding from the overpass, its contents spilling from southbound Interstate 95 to northbound I-95 below.
Two 24-year-old men from New York lay injured in a BMW after the car, crushed by the trailer, tumbled down an embankment.
Many people caught in the resulting traffic jam doubtless blamed the truck driver for shutting down I-95 near the Beltway for three hours the night of Oct. 21.
They would have been wrong.
It was a typical truck accident -- meaning it was caused by the mistake of another motorist.
Last year, 80 people died in accidents involving heavy trucks on Maryland roads. About 1,520 others were injured seriously.
The leading causes, state transportation officials believe, were not the stereotypical culprits -- poorly maintained trucks or aggressive truck drivers, although both remain a problem.
The majority, perhaps as many as two-thirds, are the fault of other drivers involved in the accidents, according to national and Washington-area studies.
The state doesn't tally who is to blame in fatal accidents involving trucks. However, a recent survey of dozens of truck accidents on Maryland's major highways this summer found that in most cases, the truck driver was blameless.
"The fact is most truck accidents do not involve a situation where the truck driver is at fault," said Thomas Hicks, head of the State Highway Administration's Office of Safety and Traffic. "Usually, somebody else is at fault."
Yet the risks posed by trucks are substantial. Trucks account for 8 percent of all traffic, but accidents involving trucks are more likely to result in serious injury or death because of their size, the force of collisions involving them and the possibility that a truck is carrying hazardous materials.
Since 1985, the number of trucks involved in accidents annually has dropped from 10,238 to 6,639. The number of deaths in accidents involving trucks has fallen from 121 to 80, about one-eighth of all accident fatalities.
Those numbers have fallen gradually, despite the increase in the number of trucks on Maryland highways. Last year, trucks traveled an estimated 3.3 billion miles on state roads, 43 percent more than in 1985.
"I can't say trucks are never at fault in accidents, but the perception is always that if a truck's involved, a truck's at fault," said Walter C. Thompson, executive vice president of the Maryland Motor Truck Association. "No matter who's at fault, an accident involving a truck is more likely to tie up traffic, and that's what people remember."
Washington-area commuters share vivid memories of the aftermath of a tanker truck's slamming into the back of a Ford Taurus on the Interstate 270 ramp from the Capital Beltway. The truck veered into a bridge abutment, and 6,000 gallons of fuel exploded into flame.
Three people died in the Oct. 19, 1992, inferno near Rockville, including the truck driver. It provoked an outcry from automobile drivers fed up with big rig traffic.
Probably less well remembered was a subsequent accident report in which the state police blamed the driver of the Taurus, a 56-year-old Ohio man, not the truck driver.
Traditionally, efforts to prevent accidents involving trucks have been geared toward making sure trucks are not overweight or operating with defective or worn equipment. A state-run inspection program also checks on the alertness of drivers and on the proper handling of hazardous materials.
More than a third of trucks checked in Maryland in 1992 were taken out of service for failing an inspection, and 4.3 percent of drivers were sidelined, most because they had worked more than the maximum 10 hours straight.
Since last year, the federal government has made it tougher to get a commercial driver's license, with more extensive written and driving tests and greater penalties assessed for traffic violations.
"Drivers of big rigs have to be held to a higher standard, and trucks need to be in better shape than cars," said Capt. Raymond Cotton, commander of the state police commercial vehicle enforcement division.
"When they get in a crash, the consequences are more serious, especially for the passengers of the other vehicles."
The inspection program has gradually reduced the number of defective trucks -- 59 percent were taken out of service in 1986 for failing inspections, compared with 39 percent last year.
But equipment failures cause only 8 percent of serious truck accidents, Mr. Hicks noted. Further reduction, he said, means addressing the behavior of other motorists.
Impatient car drivers often fail to recognize a truck's limited maneuverability, truckers say, and weave around trucks, tailgate ignore a trucker's blind spots.