A two-alarm fire in a duplex home at 818 Chestnut St., Emmaus, sent three residents and three firefighters to Lehigh Valley Hospital June 3 and caused severe damage to the home.

Every firefighter’s worst fear, a “flashover,” where fire envelops a structure without warning, occurred shortly after firefighters began interior firefighting efforts and necessitated an emergency evacuation of the structure to allow accountability of all firefighters at the scene.

After all fire personnel were accounted for, three Lower Macungie firefighters were transported for treatment of burns, smoke inhalation and an ankle injury to a firefighter. Amateur cell phone video of the fire, at the moment of the flashover, showed flames cascading from the structure to the height of a an electrical transformer on a utility pole at the curb in front of the home. Three residents of the home were also transported to the hospital for smoke inhalation and for non-life-threatening injuries.

Western Salisbury Volunteer Fire Company Chief Joshua Wells was one of the first chief officers on the scene and was given command, directing firefighting efforts by Emmaus, Lower Macungie, Vera Cruz and Western Salisbury volunteers.

A cascade unit from South Whitehall’s Woodlawn Station was on scene to refill air cylinders for firefighters. A rapid intervention team for firefighter rescue came from Alburtis Fire Department and secondary RIT teams were dispatched from Allentown Fire Department and Greenawalds when the emergency evacuation was sounded.

Emmaus and Salisbury police were on scene and medics from Emmaus Ambulance Corps, Cetronia Ambulance Corps, Macungie Ambulance Corps and Upper Saucon Ambulance Corps treated the injured at the scene and provided transport to the hospital.

Emmaus and Macungie fire police units closed Chestnut Street until fire units cleared the scene after about two hours.

The fire, which appears to have started in the basement of the home, is under investigation.

Lehigh County tax assessment records indicate the home is owned by Jerry and Ann Warmkessel, of a non-Emmaus address.

Names of those transported to the hospital were not available.