A German tourist’s Hawaii vacation took a deadly turn after a shark attacked her while snorkeling. The woman's arm was severed from her body. The Maui shark attack is the fifth of 2013; experts continue to blame poor underwater visibility for the upsurge in attacks, the Honolulu Star Advertiser reported.

"We heard screaming from the water and it was this unbelievable scream like I've never heard before," witness Andree Conley-Kapoi told Hawaii News Now. "I stopped working and I said the only time anybody would scream like that would be if they were being attacked by a shark."

The 20-year-old female victim was transported to the emergency room at Maui Memorial Medical Center where doctors marked her condition as critical. After local officials closed two miles of Palauea Beach due to the attack, the waters were reopened to the public on Thursday.

Witnesses to the attack told the Department of Land and Natural Resources they could not make out the type of shark it was. Officials say this is the eighth shark attack in Hawaii this year compared to 12 in 2012. It is the fifth attack in Maui. 

According to Waikiki Aquarium Director Dr. Andrew Rossiter, the recent increase of shark attacks in Maui could have something to do with murky, choppy water caused by Tropical Storm Flossie. Poor vision may be causing sharks to get humans confused with the animal prey they usually target for meals.

"Because there's lots of food being carried in there, so they're coming closer the shore. The water's murky, they're basically biting into anything that they sense it's not a good time to be in the water," Rossiter told KHON2. "[Tropical storm Flossie was] carrying concentrations of fresh water in there and the sharks can sense what's in the water, so they'll be curious. The water visibility will be bad and they'll be basically testing out whatever's there and if you're in there, they'll test you out."