A 309-foot barge carrying 63,000 barrels of heavy oil through San Pablo Bay struck the Richmond-San Rafael Bridge on Thursday night, but the U.S. Coast Guard reported no sign of oil spilled at the scene of the accident.

The incident comes two months after the Cosco Busan, one of the China COSCO Holdings Co LTD’s cargo struck a Bay Bridge tower and caused a 58,000-gallon oil spill into the San Francisco Bay. The spill led to appreciatively 1,800 dead birds, out of which 648 died after being rescued, the Department of Fish and Games said.

The barge was heading on a foggy weather out to sea from Rodeo on Thursday, being pushed by a tugboat when it struck the Richmond-San Rafael Bridge around 6 p.m. The U.S. Coast Guard officials reported that the barge, on its name Cascades, had hit a piling on the west side of the bridge with its starboard bow.

An examination of the bridge was scheduled for this morning, after there was no initial evidence of damage to the bridge.

"Some of the things we'll look into are mechanical failures on the tugboats, human error, fatigue and other factors," Coast Guard Capt. John Long said at a news conference Thursday night, according to the San Francisco Chronicle.

All crew members had to take an alcohol test, which showed none of them was intoxicated. They will also have to take drug tests, Long informed.

The barge was pushed away from the bridge and anchored by the Coast Guard that is investigating the cause of the accident together with state officials.

The state-operated bridge was not closed to vehicles after the incident. In the past 16 years, ships have hit bridges in the bay 50 times. Eighteen of those were commercial vessels, Long said.