Claude Simard. Photo Jackie Nickerson. Courtesy Jack Shainman Gallery, New York.

Claude Simard, artist and co-founder of New York's Jack Shainman Gallery, died on Tuesday, June 24. A statement released by the gallery describes his death as "sudden." The cause of his passing has not been disclosed.

Simard and Shainman launched Jack Shainman Gallery in Washington, D.C., in 1984, with a solo exhibition of Simard's paintings. Shortly after, the gallery relocated to New York City's East Village and then to SoHo, finally settling on 20th Street in the Chelsea neighborhood in 1997. The gallery has since opened two additional exhibition spaces—a 24th Street outpost in 2013 and The School, a 30,000-square-foot former schoolhouse in Kinderhook, N.Y., with an exhibition by Nick Cave, in May. Shainman represents artists such as El Anatsui, Kerry James Marshall and Carrie Mae Weems. The gallery focuses on artists from North America, East Asia and Africa.

Simard's paintings and performances have been exhibited internationally. His work is included in the collections of the Solomon R. Guggenheim Museum in New York, the Akron Art Museum in Ohio and Montreal's Museum of Fine Arts and Musée d'Art Contemporain de Montreal.

UPDATE: The gallery has confirmed that Simard died from a heart attack.