Though not a powerful swimmer, Tyrone Fabroa loved the water and enjoyed being out on it, the cool wind in his hair and the sun on his back, relatives said.

The 35-year-old manager of the Pagliacci Pizza on Broadway in Seattle liked Jet Skiing and kayaking. Recently, he had taken up stand-up paddle boarding, a sport that's gaining popularity in the Pacific Northwest.

Fabroa, of Kirkland, was out on Lake Washington with his 19-year-old brother on Monday, enjoying the beautiful weather, when Fabroa fell from his rented paddle board and drowned.

"We don't know what happened," said Sgt. Jim Knauss, supervisor of the Marine Rescue and Dive Unit of the King County Sheriff's Office, which is investigating the death.

"It could have been anything," he said. "Maybe he breathed in some water. Maybe he drank some water. Maybe he had the wind knocked out of him when he fell off the board."

Fabroa drowned around 11:25 a.m. despite having an inflatable life vest on his waist and the efforts of two people who saw him struggling from the shore and attempted to save him, according to police.

The rescuers pulled Fabroa from the bottom of the lake, wrestled him onto his paddle board and began doing CPR even before reaching shore, said Detective Allan O'Neill of the Kirkland Police Department.

"They feel terrible because he didn't make it," O'Neill said. "But in my mind, they're still heroes."

The inflatable flotation device that was in a waistpack worn by Fabroa was not inflated, according to Knauss. "We don't know why," said Knauss. "We tested it and it worked properly. All he would have had to do is pull the cord."

Knauss said Fabroa and his brother had rented the paddle boards from a Kirkland rental company, Perfect Wave. They had been given the option of several life jackets, including a traditional life jacket and the Coast Guard-approved Revere Fanny Pack Life Vest that Fabroa chose. The brother also said they had been instructed how to use the devices, Knauss said.

When reached by phone, the owner of Perfect Wave said he had been instructed by his attorney, Nick Clapham, not to answer any questions. "There are so many things up in the air right now that we can't make any comments at all," he said.

Because a stand-up paddle board is classified as a vessel, an accident investigation to rule out criminal activity, negligence or safety violations must be conducted, according to Knauss.

He said that at this point, Fabroa's death appears to have been a tragic accident.

"Falling into water is not as forgiving as falling off a skateboard," said Knauss. "Mother Nature is pretty powerful."

Fabroa's mother, Sonia Sayson, said her oldest son was "such a good kid and so full of life."

He spent many weekends with his parents and siblings and never gave his mother "any trouble. I'm going to miss him so much," she said.

Her child's death hits especially hard, she said, because both she and her daughter are nurses.

"We help a lot of people, but we couldn't do anything for Tyrone."

Seattle Times news researcher Miyoko Wolf contributed to this report. Christine Clarridge: 206-464-8983 or cclarridge@seattletimes.com.