A boat that capsized on Lake Tahoe during a sudden June 21 storm shifted between two destinations before taking on water and overturning near D.L. Bliss State Park without issuing a distress call, federal investigators said in their preliminary report on the accident.

The National Transportation Safety Board on Wednesday released its findings on a boat that capsized in Lake Tahoe during stormy weather, leaving eight dead and two injured.

What started as a birthday celebration ended in tragedy when eight of the 10 passengers on board died after the boat capsized on June 21.

Microplastics aren’t the only culprit affecting lake clarity in Tahoe. Algae growth rises and falls naturally every summer and winter. However, an abundance of phosphorus and nitrogen act as a fertilizer for the lake, meaning algal blooms can get much higher than they should be, negatively impacting clarity.