Guatemalan volcano erupts, kills one, shuts airport

* At least one dead after volcano spews rock

* Hundreds evacuated to emergency shelters

* Coffee producers check for crop damage

GUATEMALA CITY, May 28 (Reuters) - Guatemala's Pacaya volcano spewed black ash and small rocks for a second day on Friday, after killing at least one person, forcing hundreds of families to evacuate and shutting the international airport.

The volcano, 25 miles (40 km) south of Guatemala City, erupted on Thursday evening, raining thick ash on the capital and coating the streets in a layer of gritty black sand. Store owners and residents hosed down their driveways and shoveled heaps of ash and rubble off rooftops and sidewalks.

A television journalist reporting from the slopes of the volcano died from head wounds on Thursday when he was hit by falling lava rocks, police spokesman Donald Gonzalez told reporters.

All flights out of Guatemala City were canceled due to the volcanic sand on the runways.

In villages near Pacaya -- which is normally in a state of low-level eruption and often emits a slow-moving stream of lava that attracts tourists -- around 1,600 people were evacuated on Thursday evening and some 600 slept on foam mattresses in municipal buildings and a church.

Pacaya's eruptions usually last about six hours, but volcanologists said Thursday's was its strongest blast in more than a decade and activity could continue over the next few days. They measured plumes of ash reaching almost 5,000 feet (1,500 meters) above the volcano's peak.

"We've never seen anything like this. ... You could hear the explosions of the volcano and stones that were still on fire were falling, big stones, and many people were scared," said Nestor Sican, who lives in Amatitlan, a town close to the volcano.

President Alvaro Colom told a news conference late on Thursday that three children aged seven, nine and 10 were missing after the eruption. Guatemala's Prensa Libre daily reported three dead, including the journalist, but police could not confirm the report.

Colom declared a state of emergency for the area around the volcano and civil aviation authorities closed Guatemala City's La Aurora international airport as a thick layer of sand covering the runways made takeoffs and landings hazardous.

Airport staff worked to clear runways and officials will decide later on Friday if the airport can be reopened, said Monica Monje of Guatemala's aviation authority.

Pacaya, which is close to the pretty colonial town of Antigua and farms where some of Guatemala's highest quality coffee is grown, has been continuously active since the 1960s but had not showered rocks and ash since 1998.

Anacafe, Guatemala's coffee producers' association, said it was still gathering information from growers around the volcano to assess whether there has been any damage to crops. (Writing by Mica Rosenberg; editing by Catherine Bremer and Todd Eastham)