(Robert Casillas/The Daily Breeze/AP Photo)

After a day of heavy rain, a Los Angeles street tumbled into the Pacific Ocean Sunday afternoon, leaving a gaping hole on the cliff side.

Power lines began to sway around 3 p.m. Sunday when a 900-foot stretch of Paseo del Mar, a popular scenic coastal bluff route in San Pedro, about 20 miles south of downtown Los Angeles, finally gave way after months of creeping toward the ocean.

Mayor Antonio Villaraigosa said there were no injuries and no property was damaged. However, Peter Sanders, spokesman for Villaraigosa, says the coastal bluff that fell into the sea is likely irreparable and a new route for the scenic roadway will be considered.

The cause of the landslide is still unclear, despite all the rain that fell Sunday, and officials say it could take months to get a definitive answer.

“Today the city will hire an outside geo-technical firm to conduct an independent study to determine the cause of the landslide,” Department of Public Works spokesman Richard Lee said. “Though the work will begin today or tomorrow, we will not have a definitive conclusion for up to six months.”

City engineers say the landslide along the Palos Verdes Peninsula began during the summer, with the land moving at a rate of 4 inches a day both horizontally and vertically. Signs were posted warning residents to stay away from the unstable area while city workers rerouted drains on the 900-foot section of the road.

“The county of Los Angeles is rerouting two major storm drains, and the city of Los Angeles’ Department of Water and Power removed and relocated the electrical lines,” Moore said.

Even with no definitive answer about the cause, officials say the landslide wasn’t much of a surprise for them.

“We’ve been monitoring it and we anticipated there could be a slide,” said Gary Moore, a Los Angeles city engineer. “It’s not a total surprise. It’s nature. Up and down the coast there’s a history of slides.”

There have been landslides up and down the coast, including one at Donald Trump’s golf course just 4 miles away from the current landslide. Five years ago, the 18 th hole of Trump’s golf course fell into the ocean, leaving Trump with the cost of millions of dollars to repair the hole.