Jeanie Cline loaded 15 cases of Costco bottled water, toilet paper and canned goods into a van Tuesday.

The Kakaako resident is stocking up enough food and water for her family of 10, including children and grandchildren, who live across the island, but will stay at her Hokua condominium to wait out the coming storm.

"I’m just preparing for the worst, hoping for the best," said Cline, 45, who also runs a housing service for corporate clients. "They all come to my house because my building has generators. I also have corporate clients and they have no idea how to plan. I just have a lot of people to take care of."

News that Hurricane Iselle appears to be taking aim at the Hawaiian Islands with another powerful storm following closely behind caused a mad rush at Costco in Iwilei on Tuesday.

Waimanalo resident Oxford Rafael, 33, spent nearly $700 loading up on 28 cases of water, Spam, corned beef, Vienna sausage and snacks for his three children.

"I wanted to be prepared for everybody; just in case the other guys never buy water, I get extra for them," Rafael said of the dozen family members who live at his home. "I was looking at the news and seen the eye of the storm coming towards Hawaii so it’s better to be prepared. I’m sort of panicking."

The big-box giant sold at least 3,000 cases of water in the morning and had run out of water by noon. One shopper even begged to buy a case from Cline.

"(Other customers) were snarling and glaring and giving us bad looks," she said once water ran out at Costco. "People were trying to take water off the pallet jacks while the employees were moving them. There was a little panic in the store."

In the first 45 minutes after opening, Costco had about twice as many shoppers Tuesday as it did the day before with lines out the door, said Scott Ankrom, Costco’s assistant general manager, adding that the store sold in two days as much as it typically does in a week.

"We’re doing everything we can to get merchandise into the building," he said.

At City Mill, "It’s been a zoo," said Steven Ai, president and CEO. "Even though it’s been a big rush, everybody seems to be very polite. We’ve had a steady stream of customers buying typical hurricane prevention supplies."

Frenzied customers bought flashlights, propane and generators, which were sold out early Tuesday afternoon. Sales for the kamaaina retailer were up between 40 percent and 50 percent over the past two days compared with a typical week, Ai said.

"We’ve been pulling things out of our warehouse and ordered extra from suppliers," he said.

Mike Ward, owner of Aloha Power Equipment, sold 100 generators totaling roughly $100,000 since Monday after a line of people stormed the shop.

"We have one generator left (the biggest 10,000-watt generator)," he said.

Typically the retailer sells two or three generators a day. Ward expedited another 150 emergency generators that will be on the island in about a week.

"This time around it seems worse," he said. "We sold everything out early. People seem to be unusually panicking. Normally they wait a day before it hits, but I guess people are so convinced it’s gonna hit they’re acting now. The weatherman must be scaring everyone with his forecast."