Obstacle: CSX workers check a tanker, removed from the tunnel, that had contained flammable tripropylene. Officials have speculated that the fire began at this car. (Sun photo by Kim Hairston / July 22, 2001)

The railroad tunnel fire that disrupted downtown Baltimore for three days eased its grip yesterday as firefighters pulled out almost all of the charred rail cars trapped underground, including three derailed hazardous chemical tankers that had posed the greatest risk to the city.

The clearest sign of a return to normality came at 7:05 last night, when the Orioles took the field at Camden Yards after three straight nights of canceled ballgames. By coincidence, the team had scheduled the game months ago to be "Firefighter Appreciation Day."

"We often do not recognize these men and women until disaster occurs, and as this week's train derailment and subsequent fire proved, we all are indebted to them," public address announcer Dave McGowan said at the start of the game.

But even as baseball returned and work crews neared completion of the delicate and difficult job of removing a 60-car freight train from the rail tunnel beneath Howard Street, much work remained to address the far-reaching ramifications of Wednesday's accident.

Until all the rail cars are removed, investigators could not fully review what might have caused the accident or assess the structural condition of the tunnel and the streets above it. City workers waited to begin repairs on a gaping hole at Howard and Lombard streets, caused by a water main break three hours after the train wreck.

City officials hoped to know today whether some streets that had been closed since the evening rush hour Wednesday could reopen. But they expected Howard Street to remain closed, continuing to snarl city traffic at the start of the workweek.

Last night's Orioles game provided the first traffic test as a sellout crowd of 47,234 headed to the stadium. The team plays a doubleheader at Camden Yards today, starting at 1:35 p.m.

City officials braced for problems yesterday, concerned that game traffic would clog downtown streets. But few difficulties were reported, and many fans said they hadn't left home early.

Since Wednesday, the real gridlock had been underneath downtown streets. Frustrated firefighters faced repeated setbacks as they struggled to contain the underground fire, which burned as hot as 1,500 degrees, and to reduce the risks posed by a chemical tanker leaking hydrochloric acid.

Last night, six of the train's 60 cars remained underground. But fires continued to burn or smolder in at least four boxcars containing plywood, paper and scrap. City Fire Department Battalion Chief Hector L. Torres said firefighters did not expect to fully extinguish the rail cars until they were pulled from the tunnel.

Work crews saw their first real breakthrough in that effort about 8 p.m. Friday, when three yellow locomotives emerged from the rail tunnel's north entrance near Mount Royal Avenue dragging out seven blackened boxcars - the first group of a string of 45 cars that had remained connected and on the rails inside the tunnel when several cars at the rear of the train derailed.

Overnight, crews pulled four more sets of rail cars out of the tunnel. A string of 13 cars was dragged out just after 4 a.m. yesterday, capping the long night's work.

"The north end [of the tunnel] is no longer an issue," Torres said, as weary firefighters showed signs of relief for the first time in days.

Hydrochloric acid removed

More progress came at daybreak, when work crews pulled out the first of two tankers containing hydrochloric acid from the south end of the tunnel, near Camden Yards. The second hydrochloric acid tanker, which was ruptured, was removed just before noon yesterday after workers pumped most of the acid out of it.

As firefighters trained to deal with hazardous materials stood by in protective yellow suits, CSX workers immediately wrapped the car in a huge blue tarpaulin to contain the chemical vapors.

The third chemical tanker, Car 52, was where fire officials speculated the fire started. That car had contained flammable tripropylene, but firefighters said all of the chemical in the car had burned away. The tanker, with its top severely burned, was removed from the tunnel about 3:30 p.m. yesterday.

"When you consider the magnitude of the incident ... I think we did a real good job of doing what we had to do safely," Torres said.

Crews resumed work to remove the cars last night after the Orioles game ended with a burst of fireworks. Fire officials said the work didn't pose dangers to the public, but they didn't want to startle fans if smoke suddenly appeared.