It was surprising when Dan Noyes saw the final report: the state concludes, "We may never know exactly what led to the death of the divers." But a review of the evidence and interviews with people who were there that day show what went wrong.
Forty-four-year-old Martin Alvarado was excited about his new position as a diver with the state Department of Water Resources. It was dangerous work, but it paid an extra $9 dollars an hour on top of his salary as a maintenance worker, and that would come in handy with his seven children.
"Every time he did it, he liked it, he would come home like, 'this is fun, babe, look, this is what I did today,' and he liked it. I couldn't tell him not to do it," says Sara Alvarado, Martin's wife.
One of his first assignments as a diver was to check the Dos Amigos pumping plant for tiny mussels that can clog the system with his partner, veteran diver Tim Crawford.
The plant is a crucial part of the California Aqueduct. Each of the six massive pumps can send the equivalent of two Olympic-sized pools up a steep hill each minute. Imagine the force of all this water, doubled, rushing through a single pipe in just 60 seconds.
"They went down and they didn't come back up. We just don't know what transpired down there underneath that caused this accident to happen," says Jim Thomas, San Luis field division chief.
Several state investigations did not pinpoint the cause of the accident, but there is a lot of evidence of what went wrong.
Mistake number one -- the plant managers broke the state's dive policy that says, "diving is prohibited wherever there is the possibility the divers may inadvertently enter an area of excessive velocity."
During the dive, pump number five, with its powerful suction, stayed on. In fact, over the years, the managers regularly failed to turn off the pumps when divers were in the water.
"He was telling me that they dove with the pumps on," says Louis Sanchez, a CA Department of Water Resources employee.
Martin Alvarado's close friend and co-worker, Louis Sanchez, tried to warn him just one week before his death.
"And I go, 'that's absolutely nuts, that's crazy, people are going to get sucked in there.' I go, 'don't do it, Martin. You can refuse to do it,'" says Sanchez.
"Why wasn't the pump shut down before the divers got in the water?" asks Dan Noyes.
"It was just our normal schedule," says Thomas.
The man overseeing the plant tells us their dive policy didn't specifically say the pumps should be off during a dive. He says that will be the policy in the future.
Mistake number two: the dive tender. The man who was supposed to keep track of the divers and respond to an emergency had no training and he had no experience as a diver, both violations of state rules.
The dive tender, Mark Maderios, declined to be interviewed for this report.
But using the California Public Records Act, the I-Team obtained a recording of his interview with state safety inspectors.
"At that point there I asked Tim, 'How long you guys going to be down for?' And he says. 'Uh, should be about 30 minutes,'" said Maderios in the interview.
Records show the divers entered the water at 10:10 that morning, with about 30 minutes of air in their tanks.
Maderios watches their air bubbles as they inspect the trash racks in front of pump one and move down the line.
"I proceeded right above them and I could see where they were with the bubbles that were coming up," said Maderios in the interview.
About 10 minutes into the dive, Maderios watches the divers' air bubbles sweep into pump five and disappear. He doesn't call the senior plant operator until 10:45. By this point, the divers' air supply's running out.
Mistake number three: the safety officer at the pumping plant, Bill Collins, is also one of the most experienced divers working for the state. He was supposed to take part in the dive that day, but begged off at the last minute. And, once the divers got into trouble, he was very hard to reach.
At 10:55, the senior plant operator calls the safety officer, Bill Collins. He doesn't answer his cell phone.
At 11:19, Collins finally returns the call and says he'll drive to the plant. He doesn't order the pump shut down.
"Why not turn off that pump right away?" asks Dan Noyes.
"Well, that's a question, that was probably one of our procedures we weren't clear on," says Thomas.
It takes 20 minutes for safety Officer Collins to arrive on-scene. He also spoke with state inspectors.
I didn't see no bubbles as well, and I told 'em something's wrong," says Collins.
Collins prepares to dive, to look for the two men. But he's missing a key piece of equipment.
"One of the divers had my weight belt, so I couldn't get in the water immediately," says Collins.
Collins calls for a spare, but it would take quite some time.
At 11:46, Division Chief Jim Thomas arrives. He finally orders the workers to shut down pump five and call 911.
"911 wasn't called for an hour and a half after the first sign of trouble," says Dan Noyes.
"And that was probably the weakness in our emergency procedure of everybody being clear as to what the procedure was to do in calling 911," says Thomas.
At 12:26, more than two hours after the first signs of trouble, a spare weight belt arrives so Collins can make his dive. He recovers the bodies of the two divers.
The autopsy shows they both died of asphyxia. They drowned, waiting for help.
"There was a lot of mistakes, and those mistakes cost two lives, one of them being my brother," says Alicia Alvarado, Martin's sister.
It's all very difficult for Martin Alvarado's family, but they want to know the truth.
Mistake number four: the weeds. After the divers' deaths, investigators sent down a remote-controlled camera and found a mat of weeds and other debris covering the grates in front of pump five. That same, massive amount of water was being funneled into a few, small openings. So the force of the current right at the bars was much greater, holding the divers down.
State investigators concluded, "the high velocities likely pinned them to the trash rack, where they either exhausted their air supply or their regulators were pulled from their mouths."
The machine that's supposed to clear the weeds and debris from the grates hasn't worked for years.
"They were not ready for something to go wrong. I think that's indisputable," says Cal/OSHA chief Len Welsh.
Cal/OSHA fined the plant more than $15,000 dollars, issuing several citations. Among them,
"What could they do about it? They couldn't pull them up, they couldn't communicate with them, and as you pointed out, it took a long time for anybody to get down there to see what actually happened, way, way after anything could have been done," says Welsh.
Sara Alvarado accuses managers at the pumping plant of not telling her the real story of how her husband died.
Knowing the facts now only gets her so far.
"Nothing's going to bring him back, only he knows what happened. They're going to tell me stories and more stories, and I don't care for 'em, I don't care for 'em. I have to be strong for those kids, I don't really care for whatever they have to tell me," says Sara.
The dive tender told Dan Noyes by phone: "It's tough to deal with. They were both personal friends of mine."
The Department of Water Resources has halted all dives at the plant until they work out better procedures.
To see every official report on this case, read the I-Team blog.
