MA – DUXBURY, Mass. — A Duxbury couple are being treated after being overcome by carbon monoxide early this morning.

A 60-year-old woman who called 911 around 4 a.m. from a home on Church Street in Duxbury was found barely conscious at the front door when firefighters arrived.

A 72-year-old man found unconscious inside the house was medflighted to Massachusetts General Hospital in Boston.

The woman was taken to South Shore Hospital.

Five firefighters who responded to the scene were taken to Jordan Hospital in Plymouth as a precaution.

What caused the high levels of carbon monoxide remains under investigation.