AGANA, Guam (AP) _ A 12-hour shredding by Typhoon Paka left residents of this tropical island picking up the pieces Thursday after fierce winds drove ``water through walls,'' leveling homes, knocking out electricity and causing an estimated $200 million in damage.

No deaths were reported.

At least 20 people suffered minor injuries, mostly lacerations from flying glass and other debris. Hospital officials said low barometric pressure induced nine pregnant women to give birth.

While most of Guam's 135,000 residents are veterans of past typhoons, ``I'm sure the shock will set in once they realize the devastation this one has caused,'' said Dan Delong of Guam's Civil Defense Agency.

Sustained wind reached 150 mph and instruments at Anderson Air Force Base recorded a gust to 236 mph, said Tim Craig of the National Weather Service in Honolulu. The weather service's own instruments were out of action because of a power failure.

If confirmed, that speed would topple the record on the Earth's surface of 231 mph, set 63 years ago atop New Hampshire's stormy Mount Washington.

Preliminary estimates by Gov. Carl Gutierrez put the damage at more than $200 million.

President Clinton, responding to a request from Gutierrez, declared the U.S. territory a federal disaster area, opening the way for federal relief including low-interest loans.

Volunteers joined government workers and National Guard troops in clearing downed trees, utility poles, wires and other debris from the main roadways while utility workers began a marathon effort to restore the island's electrical network.

It could be weeks before full power is restored because of heavy damage to the island's four main power plants as well as the transmission lines, Delong said. Without power to operate pumps, one-third of Guam was without water service.

Many government and private facilities, including the resort hotels, have their own emergency generators.

Preliminary estimates of 3,000 homes being heavily damaged or destroyed ``may be on the light side,'' said Delong. Most island homes are made of concrete and easily withstood the wind gusts, but many of those still had broken windows or blown open doors.

Paka swept in from the east late Tuesday and then stalled over the island before moving off to the west Wednesday morning, creating a night of terror for many.

``People just hunkered down and hung on for dear life,'' said Philip Brady, a spokesman for the governor.

``Everything was parallel to the ground, picking things up, throwing them, snapping trees like toothpicks,'' Brady said. ``When the eye passed through ... that's when all the wheels came off. It was literally driving water through walls.''

Guam, which is west of the international dateline, is 3,800 miles west of Hawaii.