A 34-foot fishing boat sank into San Francisco Bay Wednesday morning, prompting a Coast Guard response and an effort to contain the possibly hundreds of gallons of fuel that was in the boat's tank.

There's no word on how the vessel came to sink, but the Coast Guard says it sank sometime around 3 a.m. Wednesday while tied up at the Hyde Street Pier.

The pier is home to several historic boats in the collection of the San Francisco Maritime National Historical Park, but one end of it is also home to some commercial fishing boats.

The boat's masts can be seen sticking up from the water beside the pier, and there was various debris floating including what appeared to be orange life vests.

After a "sheen was observed" in the area of the sunken fishing boat, the Coast Guard says that "Three layers of containment boom and absorbent pads were deployed" to try to contain any fuel bubbling up.

The boat's tank reportedly can hold up to 260 gallons of diesel fuel.

As KPIX reports, crew members have reportedly said they believe there was much less fuel in the tank at before the boat sank.