Bruins Legend Bobby Orr Accepts ALS Ice Bucket Challenge (Photo)

No. 4 finally hopped on the ALS Ice Bucket Challenge train.

Boston Bruins legend Bobby Orr doused himself in freezing water — with a little help from his grandchildren — to raise awareness for amyotrophic lateral sclerosis.

Many other Bruins have accepted the challenge, including winger Brad Marchand, goalie Tuukka Rask and even team owner Jeremy Jacobs.