Wind and rain continued to build overnight as Iselle, which was downgraded from a hurricane to a tropical storm late Thursday, approached Hawaii from the south. With maximum sustained winds of 70 miles per hour, the storm was just shy of the 74 mph that characterize hurricane-force winds. Officials say the impact of the storm will generally be the same as a hurricane, however, with rough surf, strong winds, heavy rain and flooding.

Tropical Storm Iselle has already downed trees, caused power outages and structural damage in some areas of the Big Island near Hilo, according to About 25,000 electric customers are without power, and some homes lost their roofs as Iselle approached early Friday morning.

NOAA-hurricane NOAA image of Tropical Storm Iselle and Hurricane Julio. Photo: NOAA

Many stores and businesses closed their doors and schools converted into shelters on Thursday ahead of Iselle’s arrival. Hawaii is under its first tropical storm or hurricane warning since 1993. Officials advised residents to stay indoors.

Hawaii's storm preparation was interrupted Thursday by a 4.5-magnitude earthquake that rocked the Big Island around 6:30 am local time. In light of an earthquake and back-t0-back storms -- Iselle and Hurricane Julio, which trails just 1,000 miles behind in the Pacific -- Gov. Neil Abercrombie expressed his confidence that Hawaiians were ready to confront multiple disasters at once. "We can walk and chew gum at the same time,” he said when asked at a news conference whether the state could recover from Iselle and, at the same time, prepare for Julio.