HONOLULU (KHON2) — A 16-year-old boy is in critical condition after a civilian helicopter crashed into waters near the USS Arizona Memorial Thursday.

According to the U.S. Navy, it happened at about 10:30 a.m. in the area near the Ford Island bridge and the National Park Service Pearl Harbor Visitor Center.

Five people were on board at the time.

Witnesses tell us they saw the chopper when it was about 30 yards offshore and knew right away that something was terribly wrong.

“I could hear the propeller in the background spinning,” said Alicia Valerio. “Then all of a sudden that noise stopped and you heard a big bang.”

“It kept sputtering, very erratic flying, probably 20 yards from shore, maybe 30 feet up, looks like he cut the prop, because the helicopter dropped down and hit the water probably 20 yards offshore, sat there for about 20 seconds bobbing, then it went under,” said witness Daniel Rose. “Guys started going in the water, diving down. Two people came up.”

Shawn Winrich was enjoying the day and using his phone to take photos of the harbor when he noticed the aircraft. “It seemed out of place and not normal, so I switched to video real quick and shot the video clip,” he told KHON2. “I didn’t see parts flying. It wasn’t a real hard impact. There wasn’t an explosion. I remember thinking split-second, I’m behind a concrete barricade wall about knee-high, and I was just about ready to duck if I seen anything flying.”

Bystanders assist with rescue efforts

Within seconds the helicopter crash-landed into the water, quickly sinking with five passengers still inside. Its proximity to shore meant bystanders could jump in and rescue the passengers within minutes.

Juan Valerio said as soon as he knew the helicopter was going to crash he made a split-second decision.

“I took off running to some bystanders and handed him my phone and wallet and as soon as the helicopter hit the water, I was in it,” he said.

“I ended the video real quick because I was going to run over. I jumped the wall and ran over to the helicopter, got everything out of my pockets, and was just about to jump in, and there were a bunch of people jumping in to help,” Winrich said.

Four passengers were brought to the shore, but the 15-year-old boy was still trapped inside.

“The mother was screaming please help her son,” said Juan Valerio.

“She kept saying my son, somebody please get my son. It is just difficult to hear that,” said Alicia Valerio.

“I dove through from the pilot’s side and the back seat and saw him, and saw the seat was twisted, so it’s just instinct at this point,” said North Shore resident Chris Gardner. “I jumped in and tried to extract him and one of the Navy policemen, Brian, had a knife, and we took turns cutting on the seat belt and finally got him out.”

Once EMS arrived, the boy was taken to the hospital in critical condition.

“I just saw him and said you know, whatever it is we have to do to give him a chance, that is what we are going to do,” said Alicia Valerio.

Witnesses say without the help of those bystanders the scenario could have turned out much worse.

“It was just a few feet out into the water, so maybe 20 feet out from the actual rock shore, so real close, luckily,” Winrich said. “I hope the pilot planned that intentionally. If not, he just got lucky it was in that area, probably the best place because it was real close, easy access to a bunch of people to help if anything happens.”

Honolulu Emergency Medical Services treated a total of three patients, including the boy. A 50-year-old man and a 45-year-old woman were treated and transported to the hospital in stable condition.

Gidget Ruscetta, chief operating officer at Pali Momi Medical Center, released the following statement:

Earlier today, a helicopter crashed near the Arizona Memorial with five individuals on board, including a family of four. Three of the family members involved were brought to Pali Momi Medical Center for treatment. Two are in stable condition and one is in critical condition. A fourth family member was treated at another area hospital and released. The family does not wish to speak to the media at this time. Out of courtesy and respect for their request, we will not be providing any additional information.

The other two patients were treated and transported by the Federal Fire Department’s medical crews on their ambulances.

Operations at the Pearl Harbor Visitor Center, including visits to the USS Arizona Memorial have been suspended until further notice. No new visitors are being admitted and all boat rides have been canceled.

How did this happen? Investigation underway

The Federal Fire Department and security personnel immediately secured the area. On Friday, crews retrieved the helicopter from the water. Click here for the full update.

The FAA issued a statement that the helicopter involved in the crash is a Bell 206 helicopter. FAA investigators are on their way and the NTSB has been notified.

The helicopter belonged to Genesis Helicopters, and appeared to be on a tour over Pearl Harbor. The company has been around since 1999.

According to NTSB records, neither the company nor the helicopter have been involved in any past accidents.

The helicopter can fit up to five people and specializes in “doors-off” tours, which claim to offer better viewing and photo opportunities.

We went to the the company’s office twice Thursday, but no one would talk to us.

According to Genesis Helicopter’s website, it offers two tours, one that goes around Oahu and a shorter tour that only covers the south shore. Both tours include flyovers over Pearl Harbor.

The FAA says the National Transportation Safety Board is leading an open-crash investigation to look into whether the tour helicopter was following rules and regulations before the crash.Experts say pilot had just seconds to react

When something goes wrong, aviation analyst Peter Forman says a pilot doesn’t have much time to react.

“Typically, at the altitude that helicopters cruise at, he has less than a minute to put that thing on the ground, so he was a very busy guy,” Forman said.

FAA guidelines say tour helicopters must stay at 1,000 feet or below when entering Honolulu airspace.

“If there is a power failure, all helicopter pilots are taught to auto rotate,” Forman said.

Auto rotation allows wind to flow through a helicopter’s blades, creating enough power for the pilot to move the helicopter to a safe place on the ground.

“(The pilot appears to be) looking for the place to bring the helicopter down. He’s coming down at a fairly good angle, he didn’t have a lot of choices at that point,” Forman said.

Kevin “Zippy” Dobzyniak is a helicopter pilot with more than 25 years of experience in both military and civilian ranks. He’s also spent countless hours as an instructor.

He says if given the choice, and all things being equal, he would almost always choose to come down on land rather than in the water.

From what he could see in the video, Dobzyniak said the pilot likely had less than five seconds to initiate and perfectly execute a safe auto-rotation landing.

“I wouldn’t say 100 percent every single time, but if you have a level place you can land and keep the aircraft level and upright, you always want to take that. If you don’t have the ability to land on a flat surface that is going to prevent a rollover, you may be better off going into shallow water to absorb some of the shock,” he said.

The FAA says it regularly inspects helicopter tour operators. Changes were made in 2007 after a string of helicopter crashes.

“I think we see so many crashes in Hawaii because there are so many here. It’s a thriving business with tour helicopters,” said Forman.

Among those changes, helicopters that fly over water must install floats, and have better pre-flight passengers briefings and life preservers.Crash video goes viral

Winrich uploaded his video clip to YouTube under the account “mrmotofy.” The video has since been requested and reposted by media outlets from all over the world.

He admitted he struggled with the decision to post the video. “Honestly my first thought was to help them. That’s why the video just ended,” he said. “I wanted to balance respect for what just happened. I wasn’t sure about all the complicated things, so I wanted to wait and clear my head a little bit and tried to decide if I should or shouldn’t.”

Ultimately, he said, he saw the video as a reflection of “just that amazing factor of what just happened, and then something like that, you’re right in front of it, nobody expects it to happen, but it does, and so just immediately, someone starts running to help, because that’s how most humans are. That’s our human nature generally. When something tragic happens, you want to try to help them.”

***Video from YouTube user mrmotofy***