Sen. Bernie Sanders won Alaska's Democratic caucuses on Saturday in a landslide, pulling in nearly 81 percent of the vote to Hillary Clinton's 19 percent, according to state party officials.

More than 10,600 people headed to schools and community centers around the state Saturday morning to cast votes in the caucuses, which were organized by the Alaska Democratic Party. Unexpectedly high turnout at some locations overwhelmed volunteers and led to long lines, delays and, at least in Anchorage, warnings from fire marshals.

Sanders won all 40 districts in the state by double-digit margins, according to a vote breakdown released late Saturday by the party. The strong showing for Sanders came on the heels of a visit by his wife, Jane O'Meara Sanders, and a Friday statement declaring his campaign's opposition to the proposed Pebble mine.

Supporters said a combination of grass-roots organizing and outreach to rural communities helped bolster his bid.

"I think (Sanders') message appealed to the independent spirit of Alaskans," said David Karabelnikoff, 34, an Alaska Native from Anchorage and a Sanders campaign volunteer.

Sanders also cruised to victory in the Washington caucuses on Saturday, winning more than 70 percent of the state's delegates. Hawaii also held Democratic caucuses Saturday but no results were available as of 11 p.m. ADT.

It's the second time Clinton, a former senator and secretary of state, has endured a dramatic defeat in the Alaska caucuses. In 2008, Barack Obama claimed three-quarters of the vote over Clinton.

Close to 8,900 people voted in the 2008 Democratic caucuses, and while party officials said they were expecting higher turnout on Saturday, there were some surprises.

Roughly 4,500 people showed up at the caucus site in Anchorage, twice the number recorded at the state's last Democratic caucuses in 2008.

At one point, so many people were packed into the front hallway near the registration area that city fire officials temporarily stopped voters from coming in. Anchorage Fire Department battalion chief Young Suenram said the issue wasn't the amount of space in the building, but the way people were clustering and blocking exits.

With a line of people stalled outside, Anchorage Mayor Ethan Berkowitz walked out to give an update on the situation and ask if anyone wanted to caucus outside.

"There's more folks in there than a plugged net," Berkowitz said in an interview outside the high school. "It's an amazing number of people."

Here's Anchorage Mayor Ethan Berkowitz talking about the situation at the Democratic caucus: pic.twitter.com/hpsqHL7OWF— Alaska Dispatch News (@adndotcom) March 26, 2016

Once caucusing got underway, more than 400 people in West Anchorage's District 18 had to overflow into the West High School parking lot -- leading to a minor vote-counting controversy when some Clinton supporters got confused in the shuffle.

District 18 in #Anchorage just got sent to the parking lot because auditorium was overcapacity. #AKcaucus pic.twitter.com/NnoxvBgI9l— Devin Kelly (@devckelly) March 26, 2016

In Fairbanks, where lines snaked out of the Carlson Center as nearly 1,700 people turned out to cast votes.

"It was pretty overwhelming," said caucus organizer Janelle Olson. "We had to have a moment where we had to shut the doors, essentially, because we couldn't let any more people in."

Olson said volunteers ran short on voting materials and had to go get more.

Still big lines at Carlson Center but moving better now. #fbxcaucus #akcaucus pic.twitter.com/0nnAvmPcE0— Tom Hewitt (@FDNMopinion) March 26, 2016

Unlike the quiet ballot-based voting on the state's Republican presidential preference poll earlier this month, the caucuses were noisy events, with people standing on different sides of a room, forming lines and raising hands to show support for candidates.

Once Anchorage's caucus doors opened, people packed wall-to-wall in the high school hallways, many carrying signs for Clinton or Sanders and wearing buttons. A boisterous crowd packed into the school auditorium to watch video introductions from the candidates. Chants of "Bernie" and "Hillary" frequently broke out, though the "Hillary" chants were often drowned out.

District vote tallies released by the state Democratic Party showed lopsided results for Sanders. In three districts -- in Interior Alaska, the Kenai Peninsula and Bethel -- Sanders won 100 percent of the delegates, with Clinton failing to secure the minimum number of necessary voters. Candidates had to win 15 percent of the caucuses' voters to win delegates.

At the Inupiat Heritage Center caucus site in Barrow, all but four of the 23 voters supported Sanders, said caucus district chair Abel Hopson-Suvlu. A similarly lopsided result emerged in the Northwest Alaska town of Kotzebue, where 46 people supported Sanders and seven supported Clinton, Hopson-Suvlu said.

"I think there was nice enthusiasm amongst the Sanders supporters," Hopson-Suvlu said. He added that the Vermont senator's campaign message of income inequality seemed to resonate with voters.

In Anchorage, Bill Heym, 66, was near the front of the line when doors opened at 9 a.m. at West High. He was changing his voter registration from independent to Democrat for the first time to caucus for Sanders.

"He tries to help us, not the establishment," Heym said.

Asked if Sanders could beat Republican front-runner Donald Trump in a general election, Heym said: "I think my mother could beat Donald Trump."

Army veteran Joe William, 74, standing in line behind Heym, had different opinions. He said he staunchly supports Clinton, and changing his registration from Republican to do it.

"In the military, you evaluate based on a skill set," William said, saying he thought Clinton was most qualified for the presidency.

In Sitka, one of the Democratic presidential candidates actually showed up. California developer Roque "Rocky" de la Fuente brought pizza and talked to voters at the caucus site, the Alaska Public Radio Network reported.

Gotta admire @VoteRocky2016 for talking to voters, putting in the work, and bringing pizza. #DemocraticPrimary pic.twitter.com/hrBUsnwsPS— Emily Kwong (@emilykwong1234) March 26, 2016

But Sitka still went heavily for Sanders, according to APRN -- 342 votes to Clinton's 83.

In Unalaska on the Aleutian Islands, where 36 voters showed up to caucus, caucus organizer Tammy Pound said she'd actually hoped for a bigger turnout. But Pound said there were a few other events going on in town that day.

"We're a small enough town that when people are committed to something they gotta do it," Pound said.

"Unalaska, do you copy?"Audio quality iffy when teleconferencing #AKcaucus across 500 mi of tundra, Bering Sea. pic.twitter.com/vnMor6ABOf— Hannah Colton (@hmcolton) March 26, 2016

Unalaska called in its caucus results with several other rural communities -- including Togiak, where the caucus consisted of just one person, APRN reported. That person voted for Sanders.

Prelim results from SW region: 103 votes for Sanders, 29 for Clinton, 0 De La Fuente #AKcaucus pic.twitter.com/ewUJNx58sM— Hannah Colton (@hmcolton) March 26, 2016

Sanders won 440 delegates to the Alaska Democratic Convention set for May 13-15 at the University of Alaska Anchorage. Clinton won 99 delegates to the state convention.

At the state convention, 16 of Alaska's 20 national delegates will be elected base on caucus results. The Democratic National Convention will be held in Philadelphia in July.

Correction: An earlier version of this story contained incorrect delegate counts for the state convention. It also identified David Karabelnikoff as a Sanders campaign organizer. He is a campaign volunteer.