Just after 4:00p.m. Sunday afternoon, cryptic messages visible for miles around Manhattan were written in the sky, spelling out, among other things, “Last Chance.” Out of context to millions in the streets below, the messages were slightly unnerving and deliberately vague. Curious speculation as each giant letter was traced into the sky led many to wonder what the message actually meant: An ad? A terrorist’s warning? A persistent marriage proposal? It turns out the display was part of an art project by Kim Beck called The Sky Is the Limit/NYC and sponsored by the Friends of the High Line.

The Pittsburgh-based artist and professor, already familiar to High Line fans for her recent empty-billboard-inspired Space Available project, had a series of messages drawn straight from advertising billboards written in an otherwise cloud-free sky. Messages included “Everything Must Go,” “All Sales Final,” and “Space Available.”

Beck referenced The Wizard of Oz‘s ominous sky-written “Surrender Dorothy” as a mirror to our own unease over the economy. She also noted the opportunity for positive change in creating community: “When, in Virginia Woolf’s Mrs. Dalloway, a crowd gathers to piece together skywriting, the spectacle unites disparate groups, as they cluster together to find meaning in the urban landscape. I am looking for folks to become a part of it by taking pictures.” A common sight around New York, certainly, was the skyward-staring cluster of pedestrians.

While The Sky Is The Limit/NYC is undeniably a sobering commentary on the current state of America’s economy, Beck also wanted to ensure a poetic quality to the display’s open-ended presentation and fleeting quality of fading smoke. While Beck began with the likes of “Last Chance,” the project ended on a brighter note with “Now Open.”