A handful of people who ignored an evacuation order shoveled ash off roofs, but otherwise Ensenada appeared a ghost town after almost all of its 1,500 residents fled to safer ground following twin blasts from the Calbuco volcano.

The volcano, which had been dormant for 42 years, erupted Wednesday, spewing a plume of ash more than 6 miles (10 kilometers) high. A second, spectacular outburst came early Thursday, with lightning crackling through a dark sky turned reddish orange by the explosion.

At the foot of the volcano, Ensenada was covered in thick soot, raising concerns that the ash could contaminate water, cause respiratory illnesses and ground more flights. Some roofs had collapsed under the weight of the ash.

Authorities said 30 residents refused to evacuate because of worries about their homes and animals. Ensenada was eerily empty except for a few residents in masks against the ash and the occasional horse or dog roaming its only street.

Daniel Patricio Gonzalez left town with his wife and children, but he returned to town Thursday night to assess the damage. The roof at the restaurant he manages had caved in.

"This hurts a bit, but there's nothing to do against nature. The important thing is that my family is fine," Gonzalez said.

No injuries were reported in the area and the only person reported missing after the eruptions was located Thursday. The 6,500 foot (2,000-meter) Calbuco had last erupted in 1972.

Authorities evacuated a total of 4,000 people from nearby communities, and they closed access to the area around the volcano, which lies near the cities of Puerto Varas and Puerto Montt about 620 miles (1,000 kilometers) south of Santiago.

Chile's national geology and mining service warned that people should be prepared for a third and "even more aggressive eruption."

President Michelle Bachelet, who visited the area Thursday, declared a state of emergency.

"We don't have any problems with supplies, water or sewage up to now," she said. "Our problem is a respiratory one, from inhaling all of this ash, and the fact that this ash could generate some sort of environmental contamination."

LATAM and other airline companies cancelled flights to and from Puerto Montt because airborne ash can severely damage jet engines.

Winds blew ash in a widening arc across to Argentina. Cars and streets were coated with a layer of ash in Villa La Angostura, Argentina, a small town about 56 miles (90 kilometers) northeast of Calbuco.

"We are praying that the volcanic activity will be as short as possible," said Mayor Roberto Cacault.

___

Associated Press writer Luis Hidalgo reported this story in Ensenada and Luis Andres Henao reported from Santiago. AP writers Gonzalo Keogan in Villa La Angostura, Argentina, and Eva Vergara in Santiago contributed to this report.

___

Luis Andres Henao on Twitter: https://twitter.com/LuisAndresHenao