A second person has died following the collision on the A1104 at Snape Hill, Saleby near Alford at 4.30pm on Good Friday, April 18.
The 16-year-old boy from Lincoln who was a passenger in the black Vauxhall Corsa involved died at Hull Royal Infirmary on Saturday evening.
A 70-year-old woman from Mablethorpe has also died. She was a front seat passenger in a red Ford C-Max that was involved in a collision with a white Mercedes van and a black Vauxhall Corsa.
The driver of the Ford C-Max, a 72-year-old man from Mablethorpe is in a serious condition at Queens Medical Centre in Nottingham.
A rear seat passenger in the Ford, an 11-year-old boy, thought to be from Birmingham, is in a serious condition in Hull Royal Infirmary.
A rear sear passenger in the Ford, whose age is not known, is in a serious condition in Hull Royal Infirmary.
The driver of the black Corsa, a 17-year-old man from Lincoln, is in a serious condition in Hull Royal Infirmary.
Two further passengers in the Corsa, both 17 years old and from Lincoln, suffered serious injuries and were taken to hospital in Boston and Grimsby.
The driver of the White Mercedes van, a 50-year-old man from Boston was not injured.
The road remain closed until the early hours of this morning, Saturday April 19.
Anyone who was in the area of the A1104 at Snape Hill near Alford and saw the collision itself or saw either the black Vauxhall Corsa or the red Ford C-Max prior to the collision is asked to contact the police on the 101 number or the witness hotline on 01522 558855.