NEW HAVEN, Conn. (AP) — Yale University says a piece of lab machinery that killed a student when it ensnared her hair met national safety standards, challenging the findings by federal investigators who concluded the machine lacked safeguards.

The U.S. Occupational Safety and Health Administration wrote a letter to Yale finding numerous problems in the machine shop where Michele Dufault was killed on April 12. The agency didn't fine Yale, saying it lacked jurisdiction.

OSHA says the lathe, built in 1962, lacked an emergency stop button that could shut off power and was missing physical guards to protect the operator.

Yale said Tuesday that it provided extensive machine tool training and personal protective equipment and students were repeatedly told not to use machinery without someone else present. Yale says staff inspected and maintained machines regularly.