An invaluable environmental art piece by the sculptor Andy Goldsworthy was damaged early Tuesday morning in what investigators believe was an act of arson.

The fire, which sent flames shooting high above the tree line in the Presidio, was reported at 5:30 a.m. today, as the Chronicle reports. At least four spot fires were subsequently reported around the Presidio, apparently sparked by embers being blown from the fire at the base of Goldsworthy's "Spire." The 100-foot-tall sculpture was created in 2008 out of felled cypress trees in the Presidio, and it is one of four site-specific Goldsworthy pieces in the national park.

The fire charred the sculpture, and it remains unclear whether it may need to be taken down.

In a statement to the Chronicle, the Presidio Trust said, "We are devastated that this invaluable piece of art has been damaged, and we are still in the process of determining if it can be saved."

The SF Fire Department reported that the spot fires and the blaze around "Spire" were all contained by 10 a.m., helped by damp and foggy conditions, per KPIX. The spot fires were said to be 200 feet by 200 feet each.

SFFD Battalion Chief Glenn Kircher tells the Chronicle that the sculpture still appears structurally sound. Investigators are hoping that surveillance footage from a clubhouse nearby might help them identify the suspected arsonists.

The 63-year-old Andy Goldsworthy was born in Cheshire, England and now lives in Scotland. He is known for his "land art" and site-specific works like "Spire," and the nearby "Wood Line" piece that creates a picturesque downhill trail through the Presidio using fallen trees. Along with two other pieces, "Tree Fall" and "Earth Wall," the Presidio's collection of Goldsworthy's works is the largest single group of them in the world, and are a magnet for art tourism.

Because his artworks are site-specific and sometime ephemeral, their value is difficult to estimate and much of his sold artwork is photography of his installations.

Photo: JF/Twitter