Downpours cause problems for travelers

Torrential downpours wreaked havoc on the state's roadways yesterday, caving in a Southeast Expressway off-ramp near Dorchester, causing an accident after a car was hit by flying debris on the Bourne Bridge, and halting traffic after Route 6 on Cape Cod flooded with several feet of water.

The rain, caused by a cold front, dropped as much as 2 inches an hour in some portions of the state, said the National Weather Service. Forecasters also issued a tropical storm watch late yesterday for southern New England, warning of high winds and rain from the remnants of Hurricane Ophelia, which was downgraded to a tropical storm last night and expected to pass within 50 miles of Cape Cod and Nantucket late today and Saturday.

The sporadic deluges caused a bevy of problems statewide, including a lightning strike on a Medford house and the water rescue of a Worcester family stranded in a flooded, low-lying street.

By 7 p.m. yesterday, 2.4 inches of rain had fallen in Wellesley, followed by 3.95 in Duxbury, and 4.44 inches in Bourne on the Cape; nearly an inch fell in Boston. The downpour washed out the grassy slope at the southbound exit at Granite Avenue (11A) on the Southeast Expressway, causing backups for miles.

As the gravel and dirt disappeared into the gutter, an 8-foot-by-10-foot section of roadway began to sink shortly after 10 a.m.

''One of the side slopes of the ramp system washed away because of the rain, and that started undermining the pavement," said Jon Carlisle, a Massachusetts Department of Transportation spokesman. ''That grassy hill just washed away, and subsequently you had pavement sitting there with no dirt or anything to support it. One of our maintenance [workers] spotted it and cordoned it off."

No one was injured, and cars were allowed to exit from one lane, Carlisle said.

Maintenance crews dug up the pavement, filled the hole with gravel, and repaved the lane in time for the afternoon rush hour.

A slope washout is rare, Carlisle said.

On Cape Cod, a woman was injured around 3:30 p.m. after a piece of metal flashing fell from the Bourne Bridge, hitting her 1999 Chrysler Sebring.

The driver -- Deanna Gilman, 35, of Guilderland, N.Y. -- was taken to Tobey Hospital in Wareham with minor injuries, State Police said.

The accident, which caused a multiple-car collision, closed the Bourne Bridge intermittently throughout rush hour and backed up traffic for miles.

State officials are trying to determine whether wind was a factor.

Shortly before the bridge accidents, rain flooded the eastbound lanes of Route 6 off the Sagamore Bridge into Cape Cod.

The low-lying lanes leading off that bridge filled with several feet of water, said Carlisle.

Eastbound lanes closed for about 90 minutes.

Southeastern Massachusetts bore the brunt of the harsh weather yesterday, meteorologists said.

''It's a sign of how much moisture was in the air that such torrential rain was able to be created," said National Weather Service meteorologist William Babcock. ''When you get a very juicy air mass, such as what we have in place, such rainfall amounts are possible. We've had them before, early [in] the summer."

Lightning also struck a home in Medford at 10:41 a.m., shattering its chimney and raining bricks on parked cars, said Medford Deputy Fire Chief Lawrence Bova. No one was injured, and there was no fire, he said.

In Worcester, heavy rains filled a section of Grafton Street with 4 feet of water, trapping a motorist and her two young children, said Lieutenant Louis Lopes of the Worcester Fire Department.

''The minivan was floating; it wasn't solidly on the ground," Lopes said.

''The small children were over their head, and the mom couldn't carry both of them."

The Fire Department rescued the family, and no one was injured.

Meanwhile, state officials concerned about the deadly Eastern equine encephalitis virus, carried by mosquitoes, said they won't be considering an aerial attack on the bugs until the rain ends.

''We might be looking at a more extended period of rain, which means it'll be longer still before we make a decision," said Bela Matyas, director of the Massachusetts Department of Health epidemiology program.

Ophelia, which meteorologists anticipate will not make landfall, will be comparable to a powerful northeaster, meteorologists said.

Mac Daniel and Megan Tench of the Globe staff contributed to this report. Adrienne Samuels can be reached at asamuels@globe.com.