Pam Panchak, Post-Gazette  A repair crew works near a ruptured natural gas line at Point State Park near Commonwealth Place today. Click photo for larger image. Listen in Listen to natural gas spew from the ruptured line in this audio report on the Point State Park leak

Construction crews ruptured a gas line at Point State Park today, forcing brief evacuations at nearby Downtown buildings. Gas crews had the line shut off within 45 minutes of the 11:48 rupture, and all the affected buildings were back in business by early afternoon.

One lane of Commonwealth Place near the Hilton Hotel remained closed this afternoon as repair crews continued to work.

The Hilton was ordered to evacuate and people left the State Office Building. The Post-Gazette also was briefly evacuated.

People were kept away from the area during the rupture, which sent the odor of mercaptan, used to reveal the presence of natural gas, through the area. The escaping gas sounded like a loud jet engine.

For a time, a bridge over the park was closed and traffic was not allowed to go past Stanwix Street toward the Point.

Pittsburgh Fire Chief Michael Huss said firefighters went through buildings with meters to make sure gas levels were safe. He said no buildings have shown explosive levels of the gas.

The line is located near the front of the park next to Commonwealth.

Power Contracting of Carnegie is the electrical contractor doing the work, according to state Department of Conservation and Natural Resources spokeswoman Christina Novak. The operator was using a ram hoe to break up the sidewalk in preparation for installation of electrical lines, Ms. Novak said. She said a review of the accident is under way, and she does not know whether the contractor was aware of the gas line or the exact circumstances of the rupture.

The operator jumped from the cab and ran after he hit the line.

The gas company reported that the gas was turned off at a valve at Commonwealth and Penn Avenue at 12:30 p.m.

Dave Spigelmyer, Equitable Gas spokesman, said the break occurred in a 20-inch line, which he called a fairly large line but not a high-pressure line.

He said the gas would dissipate fairly quickly once the gas was shut off.

Mr. Spigelmyer said the line was right under the sidewalk, which was marked in yellow to show the location.

Health officials said the gas itself doesn't pose a health problem.

"We don't thnk there would be any short or longer term health concerns as a result of inhalation. The main concern was the danger of explosion," said Guillermo Cole, spokesman for the Allegheny County Health Department.

More details in tomorrow's Pittsburgh Post-Gazette.