Federal officials close river after mysterious deaths of California family and their dog

The mysterious deaths of a Northern California family of hikers and their dog have led federal officials to close 28 miles along the Merced River, where high levels of toxic algae were detected. The announcement comes just days after officials closed access to trails in the area due to  "unknown hazards" 

The Bureau of Land Management closed campgrounds and recreation areas along the river, between the towns of Briceburg and Bagby, Friday after receiving test results of water samples downstream from where the family died. Closure to the Merced River's recreation areas will stay in effect until Sept. 17. Algal blooms can form in waterways that are shallow and warm.