EL PASO, Texas >> The FBI plans to question hundreds of patients who may have witnessed a shooting at a West Texas veterans’ clinic that left two people dead, including the suspected gunman, the agency said.

The FBI is leading the investigation into the Tuesday afternoon shootings at the El Paso Veterans Affairs Health Care System clinic at Fort Bliss. Agents have provided no information on the dead or a possible motive for the shooting.

“We’re trying to expeditiously get through those hundreds of witnesses to find out details about this incident,” said Douglas Lindquist, special agent in charge of the FBI’s El Paso office

Investigators have not said whether the gunman killed himself or was killed by someone else. They took no questions from reporters during a Tuesday night news conference.

The El Paso clinic came under scrutiny last year after a federal audit showed it had some of the nation’s longest wait times for veterans trying to see a doctor for the first time. A survey of hundreds of West Texas veterans last year found that they waited an average of more than two months to see a Veterans Affairs mental health professional and even longer to see a physician.

U.S. Rep. Beto O’Rourke commissioned that survey of more than 690 veterans living in El Paso County. O’Rourke also was active in a congressional probe into long wait times in the VA health care system.

In a statement issued by his office Tuesday, the El Paso Democrat said his “thoughts and prayers are with the men and women at the El Paso VA clinic.”

The VA said in a statement that it “is deeply saddened by the tragic situation that has occurred in El Paso, and we are actively working with our partners at Fort Bliss to investigate this matter.”

“The safety and continued care of our veterans and the staff will be our focus throughout this situation,” the agency said.

The VA clinic will be closed Wednesday, said its acting director, Peter Dancy.