John Singer Sargent's monumental painting of soldiers in the aftermath of a World War One gas attack - simply titled Gassed - arrived Friday at the Pennsylvania Academy of the Fine Arts, a somber harbinger of a major exhibition.

Gassed, by John Singer Sargent.

The journey was no mean feat.

More than 20 feet long in its original frame, Gassed arrived encased in a huge, sturdy wood crate, "Fragile" stamped on the side.

Normally, the painting hangs in London's Imperial War Museums. But in connection with PAFA's enormous exhibition, "World War I and American Art," opening on Nov. 4 and running through April 9, Gassed has made an arduous trip to the United States.

It is only the second time the painting has been on U.S. soil since Sargent completed it in 1919. (The first visit was in 1999, when it traveled to the National Gallery of Art in Washington D.C. and the Museum of Fine Arts in Boston for a major Sargent retrospective.)

A painting of blinded and writhing soldiers is not the usual Sargent fare. He is an artist more known for his society portraits, such as the Philadelphia Museum of Art's Frances Sherborne Ridley Watts (1877) or the Academy's own Mr. and Mrs. John White Field (1882).

Gassed is like none of these.

It depicts a line of badly injured soldiers in the wake of a mustard gas attack, bandages over their eyes, the blinded leading the blinded, along a board laid out near a field hospital.

The painting not only evokes Pieter Bruegel's The Blind Leading the Blind (1558), it has a frieze-like, sculptural quality - as if these wounded figures were emblems for a horrific contemporary Parthenon.

This is a frieze for the house of the near-dead.

How did a bourgeois painter like Sargent end up creating such a painting, lending it an almost allegorical tone?

Judith Thomas, director of exhibitions, said that Sargent was asked by Prime Minister David Lloyd George to create an epic painting on the subject of Anglo-American cooperation.

The United States had entered the war in 1917. (Next year marks the centenary commemorated by this exhibition, curated by former PAFA curator Robert Cozzolino, independent curator Anne Knutson, and David Lubin, professor of art at Wake Forest University.)

Sargent was at first reluctant to accept the commission, Thomas said, but finally agreed, traveling to France in 1918. At first, he complained that it was virtually impossible to find an epic scene on such a subject.

For one thing, there were few soldiers on the battlefield in the daytime.

"How can one do an epic without masses of men?" Sargent wondered in a letter. "Excepting at night I have only seen three fine subjects with masses of men - one a harrowing sight, a field full of gassed and blindfolded men."

Sargent found his subject in the harrowing. He received permission to proceed, and in 1919, produced the extraordinary canvas that arrived at PAFA Friday."It's a huge painting," said PAFA's Thomas, depicting "the hell of remembrance."

Sargent was 63 when he completed the work.

On Friday, after wheeling the crated painting on a pair of dollies into a gallery in Hamilton Hall, a team of eight art handlers dismantled the crate, carefully removed taped plastic covering, lifted the canvas out of its massive traveling nest, gently placed it on the floor, and then tipped it up and forward.

Within 50 minutes Gassed was set within its original frame and had been placed on the wall, its image of stumbling, sickened soldiers dominating the room.

Over the shoulders of the bandaged and stricken men, other soldiers play soccer in an open field; it is a routine afternoon as the sun sets, casting all in a warm glow.

"It's visually harrowing," Thomas said.