Several opponents of Enbridge’s Line 3 pipeline were arrested Tuesday morning after they put up a 25-foot-tall tipi with someone “locked” to the top of it, at a site in Carlton County where they say Enbridge is storing materials for the project. Honor the Earth says the group planned to block trucks carrying pipe into the area. The Carlton County Sheriff’s Office says the property owner asked protesters to leave and when they refused, three people — one from Duluth, one from Owatonna, and one from the state of Hawaii — were arrested and charged with trespassing.