NEWMARKET, Ont. - A man accused of drunk driving in a horrific crash that killed three young children and their grandfather has pleaded guilty to six charges.

Marco Muzzo, 29, nodded and murmured in agreement when asked if he understood the consequences of his plea.

Muzzo faced a dozen counts of impaired driving and six more charges of dangerous operation of a motor vehicle related to the Sept. 27 crash.

He pleaded guilty to four counts of impaired driving causing death and two of impaired driving causing bodily harm.

Nine-year-old Daniel Neville-Lake, his five-year-old brother Harrison, their two-year-old sister Milly, and the childrens' 65-year-old grandfather, Gary Neville, died after the van they were in was T-boned by an SUV in Vaughan, Ont.

The children's grandmother and great-grandmother were also seriously injured in the crash.