Yesterday, they found two teen-age brothers who were swept a mile downstream from Momilani Community Association on Hoomoana Street.

They were rescued by Tauamalo Sua's grandsons.

"It was flowing maybe 30 to 40 knots," Waiau fire Capt. Edward Amina said. "If the boys were hurt, we would have had a hard time finding them in deep water under all the debris.

"The Sua family has done this before," he added. "They deserve all the credit."

Harvard Kekua Jr., 14, and his brother, Alika, 15, were in good condition except for some scrapes and bruises, their mother, Patricia Nagle, said.

When the younger Kekua slipped and fell into the culvert, his brother jumped in to help him, Nagle said.

The flow could have swept them into Pearl Harbor had Brandon Bird, 14, and Jack Masaniai, 17, not heard their cries for help.

They reached the brothers with a rope at a nearby bridge, where the culvert widens.

Sua recalls her husband, Teofilo, rescued three people from the culvert four or five years ago.

"The water runs very strong when it rains so we're always watching," Sua said.

A 23-year-old Hawaii National Guard mechanic at Wheeler Army Air Field also escaped serious injury during yesterday's thunderstorm, which swept through Central Oahu.

While standing at the rear of a CH-47 Chinook helicopter during an engine test, the mechanic was knocked unconscious by lightning.

"I saw a flash of lightning go straight down and from the view I had, it looked like it struck him," said Eric Crisostomo, who was about 100 yards away. "I saw him drop. When I got to him, he was already going into convulsion."

The mechanic is in satisfactory condition at Tripler Hospital. He was being kept overnight for observation, Tripler spokesman George Vidis said.

"When the (helicopter) blades are turning, it creates static electricity and that might have been a draw for the lightning," said Lt. Col. Daniel Oshiro, acting facility commander at Wheeler Air Field.

The heaviest period of rainfall during yesterday's unseasonable thunderstorm was from 1-3 p.m., National Weather Service lead forecaster Roy Matsuda said.

Lualualei, which normally receives about a half-inch of rainfall in a month at this time of year, got 2.53 inches yesterday. Waiawa got 1.92 inches and Mililani, 1.04 inches.