SANTIAGO, Chile (AP) _ A powerful storm drove some 60,000 people from their homes during a midweek rampage across central Chile, flooding low-lying parts of the capital with the heaviest rains in years.

Three days of rain tapered off Wednesday after soaking Santiago and a wide swath of the countryside as heavy snow blocked border crossings with Argentina. The storms, which brought high winds, signaled the approach of winter in the South American hemisphere.

President Ricardo Lagos delayed a flight to Colombia for a regional summit and surveyed inundated farm fields and slum neighborhoods by helicopter, ordering the armed forces to help after declaring an emergency.

``The army has spread out to the affected neighborhoods, and is working at the task of removing the mud,'' Lagos said. While tens of thousands of Chileans remained displaced for a second day, many others began returning home as floodwaters receded.

Health authorities warned Thurdsay of a possible outbreak of influenza and other respiratory diseases, saying a combination of cold weather and flooded homes made the elderly and young particularly vulnerable.

In the capital, the storm cleared the air and afforded unusually sparkling clear vistas of the snowcapped Andes mountains, giving residents a reprieve from the gritty smog that envelopes Santiago much of the year.

At higher elevations in the Andes, heavy snowfall was reported. On Wednesday, key border crossings with neighboring Argentina were closed and some 300 trucks stranded. On the Argentine side, authorities reported up to 6 feet of snow fell in some places, and resort owners rejoiced at the prospect of a surge in skiers.

Interior Minister Jose Miguel Insulza said the storms, affecting a large portion of central and southern Chile, were among the worst in 20 years and had left some 39,400 homeless in the interior _ the rest in or near the capital.

Hundreds of army conscripts, backed by teams using heavy equipment, were dispatched Thursday to the hardest-hit neighborhoods. The soldiers joined civilians in bucket brigades that cleared water from homes and used shovels to remove mud and debris from neighborhoods and clogged storm drains.

Army trucks were enlisted to move entire homeless families and calls went out for donations of roofing materials, bedding, clothing, canned foods and disinfectants to clean schools inundated by backed up sewage. Many merchants spent the day clearing away water and debris outside their shops.

Some of the homeless were placed in a new community of small homes that was built as government housing, and thrown open to the public ahead of schedule.

Maria Iturra was among the storm victims who pleaded for government assistance. ``Our mayor must help us, it is his obligation,'' said Iturra, who said her modest home was already in bad shape from past rains.

Elsewhere in the capital, most schools suspended classes for a second day Thursday and university students heeded a government call to take part in an aid campaign for the victims. The government opened a bank account for donations.

Santiago and the neighboring Pacific port of Valparaiso were declared disaster zones, which will free $2 million in government aid. Valparaiso was hit by flooding, while landslides were reported outside that city.

On Wednesday, some 75 percent of the streets in the capital were flooded at the storm's height. The Mapocho River, which crosses through the capital, overflowed its banks, flooding fields outside the city. Many routes into the capital were closed because of the water.