Experts say the combination of a structure that’s more than 850 years old, built with heavy timber construction and soaring open spaces, and lacking sophisticated fire-protection systems left firefighters with devastatingly few options Monday once the flames got out of control.

“Very often when you’re confronted with something like this, there’s not much you can do,” said Glenn Corbett, a professor of fire science at John Jay College.

Fire hoses looked overmatched — more like gardening equipment than firefighting apparatus — as flames raged across the cathedral’s wooden roof and burned bright orange for hours. The fire toppled a 300-foot (91-meter) spire and launched baseball-sized embers into the air.

While the cause remains under investigation, authorities said that the cathedral’s structure — including its landmark rectangular towers — has been saved.

Some of the factors that made Notre Dame a must-see for visitors to Paris — its age, sweeping size and French Gothic design featuring masonry walls and tree trunk-sized wooden beams — also made it a tinderbox and a difficult place to fight a fire, said U.S. Fire Administrator G. Keith Bryant.

With a building like that, it’s nearly impossible for firefighters to attack a fire from within. Instead, they have to be more defensive “and try to control the fire from the exterior,” said Bryant, a former fire chief in Oklahoma and past president of the International Association of Fire Chiefs.

“When a fire gets that well-involved it’s very difficult to put enough water on it to cool it to bring it under control,” Bryant said.

And while there’s a lot of water right next door at the Seine River, getting it to the right place is the problem, he said: “There are just not enough resources in terms of fire apparatus, hoses to get that much water on a fire that’s that large.”

Because of narrower streets, which make it difficult to maneuver large ladder fire trucks, European fire departments don’t tend to have as large of ladders as they do in the United States, Bryant said.

And what about President Donald Trump’s armchair-firefighter suggestion that tanker jets be used to dump water from above on Notre Dame?

French authorities tweeted that doing so would’ve done more harm than good. The crush of water on the fire-ravaged landmark could’ve caused the entire structure to collapse, according to the tweet.

Other landmark houses of worship have taken steps in recent years to reduce the risk of a fire.

St. Patrick’s Cathedral in New York City, built in 1878, installed a sprinkler-like system during recent renovations and coated its wooden roof with fire retardant. The cathedral also goes through at least four fire inspections a year.

Washington National Cathedral, built in 1912 with steel, brick and limestone construction that put it at less risk of a fast-moving fire, is installing sprinklers as part of a renovation spurred by damage from a 2011 earthquake.

That cathedral faces fire inspections every two years, but D.C. firefighters stop by more often to learn about the church’s unique architecture and lingo — so they’ll know where to go if there’s a fire in the nave, or main area of the church — for instance.

“It’s really important for us to make sure that those local firefighters are aware of our building and our kooky medieval names that we use for all the different spaces and that they know where to go,” said Jim Shepherd, the cathedral’s director of preservation and facilities.

Cardinal Timothy Dolan, the New York Archbishop who often visited the Notre Dame Cathedral while studying in Europe, saw significance in the fact that the fire broke out at the beginning of Holy Week, when Christians there and around the world prepare to celebrate Easter and the resurrection of Jesus Christ.

“Just as the cross didn’t have the last word, neither — for people of faith in France — will this fire have the last word,” Dolan said.

Police say investigators on Monday arrested 19-year-old Marvin Rivas-Villanueva, who will be charged with motor vehicle homicide in connection with the March 29 crash. A passenger in Rivas-Villanueva’s car, 23-year-old Jared Williams of Lincoln, was injured in the crash and was pronounced dead at a hospital.

Rivas-Villanueva and two others were injured.

The crash occurred when Rivas-Villanueva lost control and spun into oncoming traffic. Police contend he was driving at least 70 mph on a wet roadway.

The flooded Loup River battered dams, bridges and roads last month, splitting the Twin River Public Schools district in two.

Many students and teachers in the district that serves Genoa, Silver Creek and Monroe are isolated from their schools as two main river crossings have become impassable indefinitely. The typical 10-minute drive between Silver Creek and Genoa now calls for a maze of detours and muddy back roads that can take about 75 minutes.

The historic floods have caused an estimated $1.4 billion in damage across Nebraska, drawing federal disaster assistance.

Superintendent John Weidner Sr. said the district couldn’t wait months for the floodwaters to recede so crews could repair the damage. He said administrators quickly hatched a plan to direct students and teachers stranded north of the Loup River to a Genoa school, while those south of the floods would report to an underused elementary school in Silver Creek.

Teachers were trained to deliver lessons though video conferencing, while some swapped roles with their counterparts living in the towns that they formerly commuted to. Teachers email tests and communicate with students by Facebook and text messaging.

“We had to do something to get the school up and running again,” Weidner said. “We thought we could pull this off.”

A main highway splitting the towns isn’t expected to reopen until next fall, so the district plans to salvage the remaining weeks of the 2018-2019 school year through the virtual classes.

Kirk Hebda, a 13-year-old student who is attending the alternative school in Silver Creek, said the distance learning can make certain classroom interactions difficult.

Kirk said “in some classes it’s harder than others to learn what the teacher’s teaching.”

“Like in math, you can’t interrupt his lesson to ask him questions,” he said. “And in art right now, we’re working with paint. You have to mix paint. So you don’t know if you have the right color or not that the teacher wants.”