One moment, the 56-year-old engineer was sitting alone in the cab of his Amtrak locomotive pulling six coaches on an unremarkable run from Baltimore to Washington.
The next, he was showered with tiny slivers of glass as two of his windows shattered, the sound like a gunshot in the cab. James M. Walker could barely see the tracks in front of him and had to stop a train hurtling forward at 90 mph.
Another run through Baltimore. Another encounter with what Amtrak has labeled as the nation's worst neighborhood for "stonings."
"It scares the hell out of you," recalls Mr. Walker, a Cockeysville resident. "We stopped to make sure I was OK. Then we brushed out the glass and went on to Washington. There's not much else you can do."
Mr. Walker wasn't hurt in last month's incident. It wasn't even the first time his cab has been hit by rocks, likely thrown by the two young boys he had seen seconds earlier on an embankment.
But it was a reminder that trains running along the northeast corridor face a gantlet when they come to Baltimore. Rocks, bottles, cans, railroad spikes, bricks and cinder blocks -- you name it -- can come raining down on trains at any moment.
The 3-mile run from Pennsylvania Avenue southwest to Wilkens Avenue is notorious among engineers. Amtrak rates the West Baltimore section its worst "problem area" for rock-throwing along the 24,000 miles of track its trains travel -- ahead of much larger cities like Washington, Boston, New York and Philadelphia.
"It's probably happened to me a couple dozen times in 22 years," said Ted Miller, 45, a Baltimore-based Amtrak engineer assigned to a Metroliner route between Washington and New York. "You always have to be on the lookout."
For the year ending July 31, Amtrak recorded 114 stonings of trains in West Baltimore, more than twice the number of Amtrak's second worst area, the north side of Philadelphia. It is an average of one incident every three days.
Railroad employees and passengers are usually not seriously hurt by stonings. Since the 1970s, the federal government has required glazing on all windows to prevent them from buckling, and Amtrak engineers are required to wear protective eye wear.
Last year, 35 people were injured as a result of objects being thrown at all trains nationwide, according to the Federal Railroad Administration.
But Amtrak officials worry that stonings have the potential to cause accidents. If, for instance, an engineer loses visibility at a critical moment or if the stoning causes him to panic, the result could be a serious accident.
"On a locomotive going 125 mph, the rock can pulverize the window," said Ronald E. Wiggins, general chairman of the Brotherhood of Locomotive Engineers, the engineers' union based in Cherry Hill, N.J. "Suddenly you're blind and you literally can't see where you're going. Panic is not an unusual reaction."
Baltimore's preeminence in stonings comes as no surprise to railroad veterans.
For one thing, Pennsylvania Station is the sixth busiest Amtrak terminal in the country, with 1.1 million passengers coming and going each year.
Some of the busier terminals like New York are less vulnerable because the trains are nearly inaccessible, running through tunnels or on elevated platforms.
Also, Amtrak trains headed to and from Baltimore and points south must wend their way through some of West Baltimore's toughest neighborhoods. Trains leaving Penn Station are vulnerable to attack even before they emerge from the mile-long Baltimore and Potomac Railroad tunnel near Fulton Avenue and turn southwest toward Arbutus.
A block-long break in the tunnel between Pennsylvania Avenue and Argyle Avenue near Lafayette Market, for instance, is a common site for stonings. The ravine is covered with debris: tons of broken glass, old cans and empty wine bottles, shoes, tires, a scattering of syringes, even an old copper pot.
Toss something from the overpass at either avenue and it can smack a train running at 40 mph. When police visit the tracks, they are required to wear hard hats and bullet-proof vests.
"It's frightening," said Tom Davis of Timonium, a commuter train engineer. "You see the kids with their arms cocked and you can only hope your horn is loud enough to hurt their eardrums."
Fighting such incidents is chiefly the responsibility of Amtrak Police,the railroad's private security force, but they claim budget cuts have hampered their efforts. Baltimore's Amtrak police force staffs four officers on a shift to cover 77 miles of track stretching from New Carrollton outside Washington to Perryville in Cecil County.
"The kids are usually young, anywhere from age four to 17," said Amtrak Police Sgt. Floyd M. McCargo, a former city policeman and West Baltimore native. "You have to see people perpetrate the crime to make an arrest. It doesn't happen very often."