Italian-born architect Paolo Soleri, who began building a futuristic community called Arcosanti north of Phoenix more than 40 years ago but never completed it, died Tuesday. He was 93.

Officials of the Cosanti Foundation said Soleri died of natural causes at his Paradise Valley home.

Soleri broke ground on Arcosanti in 1970 on the basalt cliffs overlooking the Agua Fria River in Cordes Junction about 70 miles north of Phoenix.

Soleri had said he dreamed of buildings and people interacting as a “highly evolved being.” The sun would warm residents, the breeze would cool them and nature would surround them. The buildings would soar, reaching toward the sky with small apartments and large public spaces.

Soleri preached community and conservation. Arcosanti would be his experiment of thousands of people living together on 860 acres of desert to teach the world how to grow. He called the vision “arcology,” a word he invented combining architecture and ecology.

But the futuristic community is only about 5 percent complete and fewer than 90 people live at Arcosanti.

There are 14 primary buildings — including some housing units, a foundry, a music center and a drafting-studio complex — plus a swimming pool with a greenhouse now being built.

“I would have been crazy if I thought it would be this slow,” Soleri told The Arizona Republic in 2010. “I am a prisoner of my own age.”