SAN DIEGO -- Alan DeWeese said his lights were on when a Coast Guard boat rammed his 26-foot Sea Ray, killing his 8-year-old son and injuring five others on board.

The lights are just one reason witnesses and survivors are struggling to understand why the Coast Guard boat crashed into the packed recreational boat Sunday night at the 38th annual San Diego Bay Parade of Lights, a popular showcase for boats decked in Christmas lights.

DeWeese had borrowed his father's boat and invited two other families to watch the parade on its 5-mile route past downtown skyscrapers and the famed Coronado Bridge. The 33-foot Coast Guard patrol boat, meanwhile, was responding to a report of a grounded vessel.

"It seemed like it was going full speed when it hit," said Barbara Maloney, who watched from her 6th-floor hotel room. "We didn't notice them slow down at all. I assume they didn't see it."

The Coast Guard has not yet provided answers. It expressed condolences to the DeWeese family Monday and said three probes were under way. The National Transportation Safety Board sent investigators to San Diego, and the Coast Guard and San Diego Harbor Police also are investigating.

"We look forward to discovering what the facts were," Capt. Thomas Farris, commander of the Coast Guard's San Diego sector, told reporters Monday.

There were 13 people aboard the DeWeese boat Sunday. Anthony Cole DeWeese, 8, died in the crash. Two other children were injured and taken to Rady Children's Hospital, and three adults were transported to University of California, San Diego Medical Center, Fire Department spokesman Maurice Luque said.

None of the five people on the Coast Guard boat were injured.

Bob Furry was watching from his hotel room when he said he saw a boat blaze across the bay with a flashing blue light.

"We said, 'Jeez, it's going really fast.' We thought it was some kind of hot-dogger," he said.

Alan DeWeese turned around, but it was too late. He estimates the Coast Guard boat was traveling 35 mph to 45 mph and that he was moving no faster than 3 1/2 mph.

"I thought, why is he going so fast? I figured he was going to turn at some point but he kept coming at us," DeWeese, 44, told The Associated Press on Monday.

"He came up so fast I didn't have time to react," DeWeese said.

Roger DeWeese said his deceased grandson had been an ice hockey goalie.

"He was a spark plug," said DeWeese, who was not on the boat during the crash. "He liked just about everything."

The boy's father, also a hockey player, said his son enjoyed life to the fullest.

The 10News I-Team searched several Coast Guard databases and found since 1998, only six boating accidents involving coast guard vessels have led to an injury. All of them took place on the East Coast. Four victims had to be hospitalized, three for being hit with the boat and one for being cut by the propeller, but all survived. In each case the coast guard vessel was moving under 10 miles per hour and in one case, the boat was docked.

According to the most recent Coast Guard annual report the service has an outstanding safety record. A review of multiple databases by the I-Team over the past ten years showed there have been more than 50,000 boating accidents in the U.S. However, it also appears the accident in San Diego Bay Sunday was different than those previously documented because the boat was moving at a high rate of speed, according to witnesses.

Many of the witnesses said the Coast Guard was going between 30 mph and 45 mph.

"I'm not going to speculate on the speed of the coast guard boat right now, I just don't have that information," said Farris.

The crew of that boat has been taken off active search-and-rescue duty.

They have been tested for drugs and alcohol, with the results pending.

During the parade in San Diego Sunday, boaters festooned their decks with Christmas lights. In keeping with this year's theme, "Christmas at the Zoo," some participants dressed up as giraffes and pandas.

There were about 80 boats in this year's parade, from a 12-foot canoe to a 157-foot yacht.

The parade drew about 80,000 people on Dec. 13 and again Sunday, said Ron Sheehan, vice chairman.