Emergency crews provided CPR to a man who collapsed at the fairway on the 11th hole Thursday at the U.S. Open at Congressional Country Club.
The incident happened just before 10:30 a.m. Maryland State Police said the man, who is in his 30s, was lying on the cart path in obvious distress.
Two officers -- Maryland State Police Trooper First Class Paul Zimmerman and Montgomery County Police Officer Deirdre Sugrue -- initiated CPR until medics arrived.
The spectator was transferred to an ambulance and was transported to a local hospital in serious condition.
The man's identity was not released.