EE WAS CHANGING OIL ON THE ENGINE OF THE TEREX 4066. HE FAILED TO PUT UP HOOD SAFETY PROP, THE HOOD FELL DOWN ON HIS RIGHT FOREARM. HE LIFTED HOOD OFF HIS ARM, CALLED FOR HELP ON COMMUNICATION RADIO. CO-WORKER RESPONDED TO HELP HIM. SENT INJURED TO UNION HOSPITAL IN TERRE HAUTE WITH ANOTHER CO-WORKER.