A member of one of Canada's wealthiest families has pleaded guilty to six charges in a crash that killed three young children and their grandfather.

Marco Muzzo pleaded guilty Thursday to four counts of impaired driving causing death and two of impaired driving causing bodily harm.

The 29-year-old had faced a dozen counts of impaired driving and six charges of dangerous operation of a motor vehicle related to the September crash.

In Canadian Business Magazine's ranking of the top 100 wealthiest Canadians, the Muzzo estate ranks 52nd, worth more than $1.7-billion.