S A N T I A G O X A L I T Z I N T L A, Mexico, Dec. 19, 2000 -- — After days of rumbling, the volcano that towers over Mexico City today struck fear into the hearts of residents who refused to leave its slopes — by lighting up “like a Christmas tree,” and spewing red-hot rocks into the air.

The Popocatepetl volcano erupted in spectacular fashion Monday night, frightening even residents who disregarded authorities’ pleas to leave the area.

A red plume continued to spew from the mountain’s peak today, and authorities warned “El Popo” wasn’t done yet.

“At first it was pretty. It lit up like a Christmas tree,” said Tomas Jimenez, a corn farmer. “Then the fear hit.”

Fury of a Friend

In his 68 years in this village just 4 miles away, Jimenez said he has come to see “Don Goyito” or “El Popo” — as residents affectionately call the volcano — as a trusted companion.

But he had never seen such fury.

“It was a little frightening, because Don Goyito was really playing,” he said.

Jimenez was one of only a handful of people to remain in the ghostly, deserted streets of Santiago Xalitzintla early today.

Packs of dogs howled at the occasional army patrol or journalist passing by, and the sky was awash in a red glow from the top of the mountain.

Flaming Shower

Although the volcano began to belch ash on Friday, it wasn’t until Monday night that it began its spectacular shower of incandescent rock.

“We got up on the roof and saw the rocks showering down. I started to get nervous,” said Cresencio Sandoval, a 55-year-old farmer. “If it continues, it might be the end of the road for us right here.”

Many of the 41,000 residents of the highest-risk zone who had refused to leave in more than 1,000 buses sent in by authorities decided that finally, it was time to go.

“We aren’t so stupid as to stay here when it gets serious,” said Cecilio Sevilla, a 26-year-old baker bundled up in a rough blanket.

He and Rita Agustin were married only Saturday and had spent four days celebrating, as is local tradition. Although Sevilla’s head still hurt from a hangover, the newlyweds realized early today it was time to go.

Sighting Lava

It was unclear how far down the flanks the lava was falling, but it appeared only about a half-mile down the slope.

“It started erupting when we left,” said one resident on his way out. “You could see the lava.”

Mexican President Vicente Fox, speaking after an emergency cabinet meeting Monday night, said some smaller incandescent particles had fallen as far as 6 miles from the crater.

“We continue on maximum alert, because this emergency is not over,” Fox said.

Some of the farm towns near El Popo were empty today. A fine layer of ash covered everything for miles around.

Staying Put

Elsewhere though, people thought it was riskier to leave than to stay. Shelters were inadequate and hard to find.

“They should have sent help a long time ago,” one woman said.

“Whenever there’s an emergency we’re forgotten.”

Rocio Tlequitalpa, a mother of four, evacuated to a nearby school, where her family shares a room with 40 other people.

“We’re much safer in here,” she said. “because you can imagine the danger we were in.”

Others feared that their homes would be looted or their livestock stolen. Many residents say police sent in to guard their belongings during a 1994 evacuation instead stole them.

Jimenez was one of them. He sent his family to Cholula, a city at the volcano’s base, and remained to keep watch on their house.

He pointed to a battered pickup truck that represented his only escape. “Here’s my transportation,” he said. “At the right moment, I’ll take off running.”

Rare Event The eruption appeared to be the largest emission of glowing rock from the peak since it rumbled back from a 70-year period of dormancy in 1994.

Scientists have warned that a dome of lava at the base of the 17,886-foot Popocatepetl is causing pressure to build inside the mountain. That could trigger strong eruptions.

“It could have been worse if this had been a brief, extremely violent eruption,” said Servando de la Cruz, a vulcanologist at the National Autonomous University of Mexico.

Geologists believe the volcano has had only three major explosions in 5,000 years. It generally does not produce flows of molten lava.

And even if this is not the fourth, lava flowing down the mountainside could melt snows near the summit and cause mudslides.

There were also fears of an ash fall among the 20 million residents of greater Mexico City, just 40 miles northwest of the peak. But Fox tried to calm fears, saying “no major atmospheric effects are expected over large cities.”

The volcano spewed a cloud of ash 2½ miles high, but it appeared to be blowing away from Mexico City.

ABCNEWS’ Ned Potter and The Associated Press contributed to this report.