UPDATE | Hurricane Joaquin upgraded to Category 4 storm

NASSAU, Bahamas (AP) — Hurricane Joaquin strengthened into a Category 4 storm today as it roared through lightly populated islands of the eastern Bahamas, and forecasters said it could grow still more intense before following a path that would near the U.S. East Coast.

There were no immediate reports of casualties as the storm reached the island chain, said Capt. Stephen Russell, the director of the Bahamas National Emergency Management Agency.

The most-severe flooding reported so far was on Acklins island, where power went off overnight and phones were down. Russell said some of the roughly 565 people who live there were trapped in their homes.

Bahamas resident Shandira Forbes said she had spoken to her mother on Acklins by phone today.

"She was calling for help because the sea was coming into her house," Forbes said. "People's roofs were lifting up. No one knew (about the storm), so there was no preparedness, there was no meeting, there was nothing."

Flooding also was reported across parts of Long Island, but no one had been injured, said Parliament member Loretta Butler Turner.