Under different circumstances, the campsite along the Petaluma River banks would look fairly inviting.

A barbecue grill stands near a large tent, both under the shady canopy of a huge live oak tree. Plastic bins contain food and other supplies. Dog treats sit on a table. A large open barrel holds brooms to keep the walkways tidy.

But the site is illegal, a homeless encampment whose residents are trespassing on someone else's property. And just over a wall of blackberry brambles lie two large piles of trash, papers, discarded food containers and dirty clothes.

It's a hard life, whether by choice or by circumstance.

Three transients have died in Petaluma within the past month, prompting concerns from police and social service agencies about what, if anything, can be done.

The most recent death appears to be a suicide. The body of a 25-year-old man was found Wednesday afternoon under the D Street bridge.

Police Lt. Tim Lyons declined to release the apparent cause of death until the man's family can be notified. The man was known to police as a local who lived on the streets. Another homeless person found his body and alerted police.

The two other deaths — the skeletal remains of a woman found on McNear Peninsula on Aug. 16 and the body of a man found in Willow Brook Creek on the north end of town — don't appear to involve foul play or violence, Lyons said. Neither person has been identified yet.

"There is nothing suspicious about any of the deaths and there is no evidence to show they are in any way linked or knew each other in any way," he said.

"The only theme is that they were all transients."

The two earlier deaths could be natural causes, medical problems or simple old age, Lyons said.

While the three deaths so close in time may seem unusual, Mike Johnson of Petaluma's Committee on the Shelterless said it is all too common.

"As tragic as it is, people dying on the street is not abnormal. That's the real tragedy," he said.

Johnson, who did not know the identity of the 25-year-old man, said the first two victims don't appear to have been COTS clients.

"I'm kind of at a loss about who these folks are, what was going on with them, why they succumbed or why this man committed suicide," he said. "We just don't know the answers."

Lyons said complaints about trespassing, theft and other crimes have increased lately and police have responded by making several arrests in or around homeless camps. Stolen property including bikes, tools and other home goods was found.

A small grass fire that threatened several homes last week near the railroad tracks behind Rocca Drive was started in an area near several homeless camps, Fire Marshal Cary Fergus said. An exact cause hasn't been determined, but he said the area has been inhabited by the homeless previously. Vacant homes adjacent to the area show signs of squatters and vandalism.

"The fire started in an area that was next to an illegal trail into the property," he said.

In the past two weeks, Petaluma police have warned the estimated 40 to 60 people living in homeless camps along the railroad tracks, the river and on the banks of other hidden creeks that they are breaking the law and must leave.

Officers give them at least three days' notice to collect or abandon their belongings, then work crews come along and cart anything left to the dump.

The camps, many along the river banks, create mounds of trash and potential contamination for the water.

One camp police toured Wednesday has blossomed into a semi-permanent structure, with plywood walls, a raised bedroom area with shelves, matching curtains and pictures on the walls. Bags of empty glass bottles apparently await recycling, while foul-smelling coolers contain untold rotting food.

"In winter, this whole creek is flowing," Lyons said, "and all this garbage washes into the river."

That particular camp's resident, who police think is in jail, hung a mummified possum carcass and fishhooks near the hidden entrance through the thicket to deter strangers.

At another camp nearby, a hand-painted sign stood at the entrance: "Polightly F--- off. This may not be a house, but it's a home."

Johnson said he and his COTS colleagues were brainstorming Thursday afternoon about the latest deaths.

"We've got to find a way we can reach out to people more effectively and try to engage them and hopefully partner with police and volunteers and other organizations to get out there more and talk to people in their camps," he said.

"The sad fact is, even if we're able to interest them in the services, we've got 50 people ahead of them waiting to get in," he said. "It's very frustrating to hear these things. It's so hard to offer them hope."

You can reach Staff Writer Lori A. Carter at 762-7297 or lori.carter@pressdemocrat.com.