Update: ACE train stranded by Niles Canyon landslide; Danger lingers in rain-soaked hills

FREMONT  -- The weather outlook improved immensely Tuesday with sunny skies over the San Francisco Bay Area, but it was merely a façade hiding the danger lurking in rain-soaked hills and swollen creeks and rivers.

Slides, minor flooding and toppling trees will continue for several days as the region dries out from rains that pelted Northern California beginning on Dec 26th.

On Tuesday morning, commuters were stranded on an  Altamont Corridor Express train by a landslide in the saturated hillsides of Niles Canyon. There were no injuries among the 220 passengers on the train that only suffered minor damage when it was struck by debris. 

According to the Alameda County Fire Department, the southbound ACE 05 train going from Stockton to San Jose ran into a mudslide in Sunol around 8:45 this morning.

"The conductor stopped and then everything just came down on one of the cars," said passenger Alex Vargas. "I think the scariest thing was just walking by that car that the landslide fell on and just seeing all of the rocks and debris."

Rescue workers say this could have been much worse.

"We are fortunate that this didn't turn into something bigger," said Alameda County Fire Division Chief Randall West. "This was actually not a train derailment, and the train had stopped due to a 100-foot mudslide." 

Selvan Subramanian, a passenger aboard the train, was on his way from Tracy to his job at Apple in Cupertino and snapped two pictures from inside the disabled train, showing mud and debris up against the side of the train car.

Passengers were transferred to another train which then returned to the Pleasanton station where ACE provided bus service to stranded passengers.

A spokesman said the ACE 05 train appeared to be in safe, working condition and the afternoon service was still being determined as crews continued to clear the tracks, with time of completion still to be determined.

Slightly more than 18 inches of rain has fallen in San Francisco over the 22-day span creating a busy time for local and federal meteorologists. The National Weather Service issued 147 significant advisories, four tornado warnings, and 215 flood advisories and warnings over the 22 days.

On Monday across the Bay Area, trees continued to fall, more hills slid, and additional neighborhoods flooded. 

Marjorie Cruz and her husband woke up to the roar of cascading mud slamming into their Berkeley hills home of more than 20 years.

"It was very terrifying when it started because it's trees and debris," she told CBS News. 

It was also stunning to Berkeley Deputy Fire Chief Keith May. 

"It's pretty sobering," he said. "23 years and I haven't seen anything like that here where it has actually taken out a home."

Over on the coast at Fort Funston in San Francisco, a concrete structure, which had been jutting out and partially buried in the sand dunes since World War II, tumbled onto the beach below.

Golden Gate National Recreation Area officials said that the structure had been undermined by the saturated soil.

The structure tumbled off the cliff around 10 a.m. Monday and slid about 200 feet, according to the San Francisco Fire Department.

David Montgomery, a professor of geomorphology at the  University of Washington, said after such a lengthy deluge, the hillsides could be unstable for some time.

"For some of the deeper, larger landslides, where it takes longer time for that water to seep down to the layers that are destabilized," he said. "It can take weeks and sometimes even months for the danger to really pass."