At least 36 people were injured, including 11 seriously, Sunday after a Hawaiian Airlines flight from Phoenix to Honolulu hit severe turbulence about 30 minutes before landing.

The turbulence sent some passengers flying out of their seats and at least one hit the ceiling.

Paramedics and emergency medical technicians treated passengers — ranging in age from 14 months to adults — for a long list of injuries, including serious head injuries, cuts, bruises and loss of consciousness.

Hawaiian Airlines said Flight 35 from Phoenix “landed safely” in Honolulu about 10:50 a.m. The plane was carrying 278 passengers and 10 crew members. It was unclear how many of those injured were crew.

Jon Snook, Hawaiian Air executive vice president and chief operating officer, told reporters the “fasten seatbelt” was on at the time of the incident. He added that three flight attendants were among those injured.

“Sometimes, these air pockets occur with no warning. It’s rare to have that level of extreme turbulence. It was a very extreme case of mid-air turbulence,” Snook said.

“We’re very thankful the extent of the injuries was not critical. It could have been worse.”

Passenger Kaylee Reyes said the turbulence hit without any warning.

Her mother had just sat down when the incident happened and hadn’t had a chance to buckle her seatbelt.

“She flew up and hit the ceiling,” Reyes said.

Jazmin Bitanga, who was on the plane flying home for the holidays, said there were actually two “intense” drops of altitude — one so strong her boyfriend’s water bottle flew into the ceiling and cracked it.

“I turned around and there was a couple of people bleeding and just bracing themselves,” said Bitanga.

“Just all around me there were people crying.”

The turbulence happened just before or at the point of descent, Snook said.

A “mass casualty emergency” was triggered, and dozens of firefighters, paramedics and the state state Aircraft Rescue Firefighting Team met the aircraft at Gate 10A.

Of those injured, 20 people were taken to emergency rooms. Eleven were in serious condition and nine were in stable condition, Honolulu EMS Director Dr. Jim Ireland said. Eight ambulances responded to take people to hospitals while a city bus was used to transport others.

“Although initially we thought there were some patients with critical injuries, after further assessment it turns out they weren’t that severely injured, which was great,” Ireland said.

“Our thoughts and prayers are with all of them and their families.”

The National Weather Service said the severe turbulence happened at about 36,000 feet.

“We believe the flight may have gone through a thunderstorm, which may have caused the severe turbulence,” said NWS meteorologist Genki Kino. “During that time, there were scattered thunderstorms everywhere.”

The incident comes as a powerful cold front impacts the state.

Snook said “there’s a lot of unstable air” surrounding the islands, but he stressed severe turbulence is uncommon. The airline did divert three other flights Sunday, but all of them were because of a lack of visibility.

He added that an investigation is ongoing to determine what happened, including how much altitude was lost. The FAA is also investigating.

“There was no warning of this particular patch of air,” Snook said.