A worker was reportedly impaled on a steel rod after a fall at a construction site on the 8800 block of Ridge Road in Bethesda.
Medics are working to stabilize the patient, who will be flown to the hospital via Maryland State Police medevac helicopter, according to Montgomery County Fire and Rescue Service spokesman Pete Piringer.
A landing zone is being set up at Bradley Hills Elementary School.
Ridge Road is closed to traffic as a result of the incident.
File photo