HAYWARD -- A "doom and gloom" note found at the home of 15-year-old twin brothers -- one possibly dead by his own hand, the other in the hospital with self-inflicted knife wounds -- states that the boys were unhappy and intended to disappear, officials said Friday.

The dead teen was found hanging from a branch, his feet still touching the ground, in a Fairview ravine. He also had superficial knife wounds on his body. A preliminary coroner's report states the cause of death was asphyxiation, Alameda County sheriff's Sgt. J.D. Nelson said.

The boy's brother was hospitalized after deputies found him in a nearby Beckham Lane house, which he had broken into and apparently tried to set ablaze about 11:40 a.m. Tuesday, Nelson said. The boy stabbed and sliced himself -- severely damaging a lung -- and urged the officers to shoot him, advancing toward them with a knife in each hand.

One of the deputies used a Taser, and the boy was restrained and taken a hospital for his injuries, where he remained Friday night.

Nelson called it an attempted "blue suicide" -- an act to provoke officers to open fire -- and credited the Taser with saving the boy's life.

Investigators soon found out that the boy had a twin brother. About that time, the note surfaced, intensifying concerns about the sibling. A canine search and rescue team found his body deep in the underbrush Wednesday morning.

The boy is not being named because, with few exceptions, it is this newspaper's policy to withhold the names of suicide victims -- although the death has "not absolutely been ruled a suicide," Nelson said.

Investigators are looking into whether the twin's brother might have played a part in the act.

"We are trying to figure out if they were both (in the ravine), and if there was an overt act (by the surviving twin)," Nelson said.

He said they also are trying to determine who penned the note, which expressed remorse for the sorrow they may cause family members and urged family members not to blame themselves.

Nelson said it stated that the family shouldn't bother to look for them because they will never be found.

"It does lead one to believe that their intention was to go to the remote canyon or somewhere and perhaps end their lives," Nelson said. However, he added that while the note mentions that both twins are going to be gone, "it does not specifically say suicide."

He said rather than a suicide note, it's more of a "state of our lives" note.

"It says they are unhappy and have been for sometime, and if they seem happy, it's been a facade," Nelson said. It did not give any specific reasons for their misery, he said.

Nelson reiterated what students at Hayward High have said about their classmates: The twins were honor students, smart, with good grades who showed no signs that there was any turmoil beneath the surface.

"They have a very decent family and a support system," he said. "No indications of anything, no real problems. ... For all of us here at the sheriff's office, it's a real head-scratcher."

"Many people wish that they could turn back the hands of time and do some kind of intervention," Nelson said.

Eric Kurhi covers Hayward. Contact him at 510-293-2473. Follow him at Twitter.com/erickurhi. Read our blog at www.ibabuzz.com/hayword.