NEW HAVEN, Conn. — A Yale University student nearing graduation was killed in a school lab when her hair was pulled into a piece of machine-shop equipment, an official said yesterday.

Michele Dufault, a senior majoring in astronomy, died Tuesday night “in what appears to have been a terrible accident involving a piece of equipment,” school officials said yesterday.

The university said the accident took place in a chemistry-lab machine shop, but didn’t say what the equipment was.