One man was killed when a Mini Cooper carrying six people crashed near Workington in Cumbria.
The car was travelling through the village of Great Clifton early on Monday, when it flipped onto its side.
The dead man was a 27-year-old passenger from the Cockermouth area, but has not yet been named by police.
All of the remaining passengers were taken to the West Cumberland Hospital in Whitehaven, where at least two are in a serious condition.
It is thought the youngest casualty is aged 14, with others aged between 17 and 26.
A Cumbria Police spokesman said investigations were ongoing into the exact cause of the crash.
The road was closed for more than six hours.