A construction worker hit a gas line while building a fence behind La Casa Italiana on Tuesday morning, prompting an evacuation of students in the house and neighboring house Xanadu. No one was injured, but the incident left officials and workers disagreeing about how clearly the gas line was marked and who was responsible for marking it.

The accident happened just before 9:15 a.m., said foreman Tim Castrillo of Sierra Lumber of San Jose. He was using a shovel to dig a hole for a fence post in a gravelly area behind Casa Italiana that will be used for bike parking. About two feet down, Castrillo hit a one-inch plastic pipe that delivers gas to the house. Castrillo called Palo Alto Fire Department, which responded immediately, according to battalion chief Geo Blackshire.

The first PG&E representatives arrived to clamp off the line at about 9:40 a.m., followed by more PG&E representatives to repair the pipe around 10:10, Blackshire said.

Meanwhile, firefighters entered Casa Italiana to conduct air tests and assess the risk of an explosion. They found no danger but smelled a light gas odor and evacuated residents, some of them still sleeping, as a precaution.

Firefighters “knocked on my door, opened the door and said, ‘Sorry to wake you, but you have to evacuate, and you have to close the windows,’” said first-floor resident Claudia Preciado ‘12 — one of the house’s 52 tenants, according to resident assistant Blake Miller ‘11.

The house’s emergency assembly point was behind the house near the site of the gas leak, so residents gathered across the street at Sigma Nu, Miller said. (Later, some residents went to the CoHo to sign the giant card they had made for one of their own, who was recently hospitalized with meningitis.) The gas was back on after lunch, Miller said.

PG&E will conduct a routine investigation, said spokesman Matt Nauman. The accident prompted plans by Larry Gibbs, vice provost of environmental health and safety, to issue a reminder to top project managers in Residential and Dining Enterprises and in the University about the importance of checking for utility lines before digging.

“It’s a good reminder to reinforce with all contractors,” Gibbs said.

A Protocol Reminder

Officials and the worker dispute how well the pipeline was marked and who was responsible for those markings. Gibbs explained how construction crews usually avoid accidents like the one Tuesday at Casa Italiana, which was built in 1976 and underwent a capital improvement project this summer.

“Anytime anyone digs into the ground, they are supposed to go through this process called USA,” which stands for “underground service alert,” Gibbs said. The process means identifying the locations of buried utility lines by marking the ground with spray paint and flags. Online USA resources can help find underground lines, Gibbs said.

“It’s common practice,” he added. “Most everyone does that.”

And the responsibility of marking the locations of utility lines ahead of work is “really on the contractor who’s doing that work,” Gibbs said. “That’s their responsibility.”

Behind Casa Italiana, yellow spray paint on the parking-lot asphalt next to the gravelly area signals the gas pipeline, and Gibbs said he recalls flag markers being in the gravelly area before the work.

But Castrillo said it was unclear exactly where the pipe ran as it approached the house. That is why, to take extra precaution, he used a shovel rather than power equipment to dig, said Bob, a retail supervisor at Sierra Lumber who declined to give his last name for what he called personal reasons.

The supervisor added that older pipelines are more difficult to locate on USA websites or with tracking equipment. Contractors can call USA organizations, who will ask PG&E to mark pipeline locations a day or two before the project begins, he said.

“There’s a lot of old pipe out there at Stanford, that’s for sure,” the supervisor said. Nauman, the PG&E spokesman, did not know how old the pipeline was.

As to whether Sierra Lumber called a USA organization to find the utilities ahead of building the fence, the supervisor called the question “irrelevant,” because the pipeline was “previously marked prior to us going out to dig these post holes.” He said he didn’t know who marked the locations.

Gibbs said spray paint or flags marking the more exact location of the pipeline in the gravelly area behind Casa Italiana might have been “obliterated” during earlier landscaping work.

Meanwhile, Rodger Whitney, executive director of Student Housing, contended the markings were appropriate. “The gas lines and other utilities in the area had been appropriately marked, as is mandated before digging occurs in a situation such as this,” Whitney said in an e-mail to The Daily. He did not respond to The Daily’s questions about who was responsible for the markings.

Ultimately, Gibbs said, it’s unusual for hand-digging to cause damage like this, “but the main thing is I think we had a very good response, by everyone from Palo Alto Fire to DPS [the Department of Public Safety] to PG&E.”

Whitney also commended the response: “While the volume of utility supply lines on our campus mean that these things do happen from time to time, the key is having the correct protocols to respond, and ours worked very smoothly today,” he said.

The number-one reminder from PG&E, Nauman said, is that “it’s important people check before they dig.”

Gas leaks at Stanford happen infrequently, Blackshire said. The University Safety and Security Report lists no gas-leak responses in its 2007-2009 fire log. Matt Geenen, the Student Housing building manager for the lower Row and the fraternity cluster between Lomita Drive and Campus Drive, said he had never dealt with one in his six years on the job.

The Contractor

Castrillo and the Sierra Lumber retail supervisor said their customer was John Arrillaga ‘60, billionaire and University donor.

“All of our work related to the University,” including other fence and deck projects on the Row and in Escondido Village, “has been one way or another connected to John,” the supervisor. “He makes a line where he wants the fence line to go,” said the supervisor.

“We’re working for John Arrillaga,” Castrillo said.

Arrillaga’s close involvement in campus landscaping projects has long been rumored among students, but University officials on Tuesday were tight-lipped about the identity of the contractor.

Geenen said Arrillaga was “a donor who helped fund” the larger landscaping project around Casa Italiana, Bob and Storey, including the Casa Italiana fence. Geenen said he didn’t know if Arrillaga was the contractor.

Gibbs also said he didn’t know who the contractor was. Responding to Daily questions via e-mail, Whitney did not address the newspaper’s questions about who the contractor was or who hired Sierra Lumber to build the fence.

Arrillaga did not return a message Tuesday afternoon at the office of his Palo Alto property management firm, Peery/Arrillaga.