An intersection along one of Baltimore's main east-west arteries will be closed for up to two weeks following a massive cave-in caused when construction on a new Metro tunnel burst underground water mains early today.
A hole, 30 feet by 25 feet and 15 feet deep, opened about 12:45 a.m. at Orleans Street and Broadway, near Johns Hopkins Hospital.
The hole, however, was not directly above the tunnel, which is being dug about 40 feet below the surface.
No one was injured, but the cave-in will cause the first major interruption of work on the subway extension from Johns Hopkins Hospital to the Shot Tower, a delay of about one to two weeks while an investigation takes place, according to a Metro official.
"What we need to do before we start tunneling again is make sure we can keep this from happening again," said Jackie Brown Moore, spokeswoman for the Mass Transit Administration.
In the meantime, Orleans Street is closed between Broadway and Central Avenue, although traffic was being detoured slowly through the area as of early afternoon.
"It looks as though the mothership has landed," one worker said as crews from various agencies gathered near the gaping hole. "This looks like something from the dark side of the moon."
Crews with cranes worked throughout the morning, lifting large pieces of concrete, bits of the road surface and old, rusted sections of metal pipe from the hole.
David Arnold, who works for the city Department of Transit and Traffic, said it was originally hoped the hole could be patched quickly and the entire area reopened to traffic. He later said it would be at least several days before it would be fixed.
Donald Strickland, a supervisor for Kiewit/Shea of Omaha, Neb., the firm digging the tunnel, said that estimates were also not immediately available of how much it will cost to repair the intersection.
zTC Ronald J. Hartman, head of the Mass Transit Administration, said there would be "a full investigation" of the cave-in.
A large section of the southwest portion of the busy intersection sank some 20 feet, taking with it sections of sidewalk pavement and a large utility pole used to support overhanging traffic signals.
The street reminded more than one person of an earthquake scene.
L "You could hear it give way above us," said a tunnel digger.
An underground natural gas line was bent by the collapsing earth, and a mild odor of gas filled the air around the hole. Baltimore Gas & Electric Co. crews responded to the scene.
Nearly a dozen workers were inside the tunnel when the collapse occurred. All escaped without injury.
The cave-in is mostly in the eastbound lane of Orleans Street, near the parking lot of a Popeye's restaurant and two blocks east of Paul Laurence Dunbar High School.
A 200-foot-long digging machine, known as a mole, was facing southwest 35 feet underground and just beyond a low-rise apartment complex opposite Church Hospital when a 20-inch water main suddenly broke, apparently from vibrations caused by the machine, Strickland said.
Strickland said torrents of water suddenly washed out the ground under the intersection, causing several of his men to retreat to an opening near Johns Hopkins Hospital in ankle-deep water.
Strickland said the mole was not damaged.
Within seconds of the initial cave-in, two 6-inch water mains several feet from the larger main also burst, sending more water into the hole, weakening parts of the intersection that have not caved in.
Strickland said his men immediately notified the city water department, which sent crews to the scene to shut off the water. City firefighters also arrived to assist.
A dispatcher for the city's Water and Waste Water Bureau said no customers called complaining of a lack of water.
However, the night auditor at the Johns Hopkins Inn, a motel used primarily by visitors to the hospital that is less than a block from the cave-in, said water there was cut off for about five hours this morning.
A nurse at Johns Hopkins' emergency room said water remained available there, but said water was also seen leaking around some elevators.
Church Hospital at Broadway and Fayette Street reported having water.
Strickland said once the endangered sections of the intersection are removed and the area stabilized, the hole would have to be filled.
He said new water mains would have to be installed or the broken ones repaired before the hole could be refilled.
"Then the earth will have to be tamped down to the original firmness before black top can be applied," he said.
"We're talking about a few weeks," a fellow worker estimated.
Hours after the cave-in, earth directly under the damaged roadway continued to fall into the hole, most of it turning to mud.
Water continued to spill out of the three broken mains and leak through the mud into the tunnel, some 20 feet below the cave-in.
Tunnel workmen who were forced to flee said there was not any real danger of being trapped. One said that when the word was passed that water was leaking into the tunnel, workers calmly turned around and walked out.
Workers assigned to specific safety tasks turned off all electrical motors to prevent electrocution and fires.
The twin subway tunnels are part of a $321 million MTA project that will add 1.5 miles to the existing 14-mile subway line, which currently runs from Owings Mills to Charles Center.
The new subway extension, which is due to open in 1994, will include two new stations, at Johns Hopkins Hospital and downtown at Baltimore and President streets, near the Shot Tower.
Work on the tunnel got under way in July. As of yesterday, workers had tunneled about 700 feet.