The San Francisco Sheriff's Department is investigating allegations of prisoner abuse at the San Bruno lockup -- a bizarre case in which a pair of gay inmates say they were "inappropriately touched" by deputies, and that a cell-phone camera was used to transmit tasteless pictures of the men to other deputies.

One department insider summed it up as little more than a case of "stupid horseplay."

Maybe, but it's prompted a very big investigation.

Sheriff Mike Hennessey said Tuesday that the allegations came to light about six weeks ago when a gay prisoner complained to a sheriff's sergeant that he had been mistreated by his guards in several incidents in February and March.

Hennessey said the department started an investigation right away. Then, according to our department insider, who spoke on condition his name not be used, a second inmate came forward and corroborated many of the first inmate's complaints. Both prisoners, who reportedly did not know each other, were transferred to other jails.

Our source said the men complained of sexually explicit comments and inappropriate touching by guards. One prisoner said a deputy had drawn breasts on the inmate's T-shirt.

One of the men said a deputy had used his cell phone camera to take a picture of a fellow guard with a prisoner, possibly while exhibiting improper behavior.

Department sources say all 18 members of the San Bruno jail's night crew were called in for sit-downs with investigators. The deputies are being represented by the San Francisco Deputy Sheriffs Association attorney, Sacramento lawyer David Mastagni.

Mastagni did not return a phone call Tuesday, and association President David Wong said he wasn't privy to details of the case.

"I can tell you up front that deputies seal their lips better than I do," Wong said. "If anyone did do anything, the investigation should have the results of what happened."

Hennessey said the two inmates had taken lie detector tests, though he would not disclose the results. He said the department can't compel peace officers to take polygraphs under California law.

From what we hear around the department, proving the case won't be easy. No camera phone and no photos have turned up, and the deputy accused of taking the pictures has denied any wrongdoing.

"I'm hopeful we will be able to find the truth of what happened," Hennessey said. "And if the allegations are proved, there will be consequences. "

As for talk around the department likening the allegations to the military's infamous Abu Ghraib prisoner abuse scandal, Hennessey said the comparison was irresponsible.

"There were no pyramids, no dog leashes, no naked bodies, no pointing at anyone's (body parts)," he said.

And for dessert? It's one of the oddest invites we've ever seen -- wine, cheese and suicide.

But that's just what the Psychiatric Foundation of Northern California is mixing this evening in an effort to draw attention to the idea for a suicide barrier on the Golden Gate Bridge.

In commemoration of the bridge's 68th birthday, the foundation is hosting a party at St. Francis Memorial Hospital featuring wine, hors d'oeuvres and models of suicide barriers designed by UC Berkeley engineering students.

Not your usual press conference, to say the least.

"Exactly," said foundation President Dr. Mel Blaustein. "The idea is to keep the momentum going.

"I wasn't sure how much press coverage we'd get, but we're getting calls, " Blaustein said.

We bet.

By the way, so far this year, 12 people have leaped from the Golden Gate, officials tell us -- including one Tuesday.

Getting virtual: Having come up with nothing on their first tests, federal inspectors are taking their probe of welds on the new Bay Bridge eastern span to a whole other realm -- the virtual world.

It's the latest chapter in the saga over allegations by more than a dozen welders that the bridge's contractor, joint venture KFM, pressured workers to cover up faulty welds to meet construction deadlines.

Both the FBI and Federal Highway Administration began inquiries into the welders' complaints, which were reported last month in the Oakland Tribune. The paper said some of the welders had told of cash incentives paid by their bosses to speed up work.

A sampling of recently completed welds, including two that welders identified as possibly defective, took three weeks but found no serious flaws.

Still, thousands more welds are encased in concrete piers under the bay - - far from inspectors' eyes.

Independent inspectors hired by the Federal Highway Administration concluded that more studies of the 24 piers buried in concrete needed to be conducted before the bridge could be given a clean bill of health.

So now the Federal Highway Administration is preparing to conduct a round of computer model tests on the welds.

Inspectors won't actually go down and look at the welds or cut open the piers. Instead, they will run a series of virtual "jolts" to the bridge to see how many good welds they need to keep the bridge safe and standing.

Federal Highway Administration spokesman Nancy Singer wouldn't say when the tests will begin or how long they will take to complete.

But even testing in the virtual realm is sure to add to the millions of dollars in extra costs that have piled up from the welding probe, thanks to construction delays and consulting bills.