At first, neighbors figured the loud sound coming from the alley between Hill Street and Piedmont Drive in Point Loma early yesterday was just the rain. Then dawn came and the source of the noise revealed itself: It was a massive water-main break that sent water gushing 50 feet in the air and created a sinkhole that swallowed a sportfishing boat and an SUV.  About 4 p.m., city crews finally scooped the 22-foot-long boat and the Chevy Tahoe out of the pit. By 7 p.m., water service had been restored to 15 homes in the neighborhood. At one point, a backhoe brought in to help clean up the mess also tumbled into the hole. It finally dug its way out.

The cause of the break was a mystery, although neighbors said they saw a water leak in the alley in recent days. "But no one called the water department, unfortunately," said Tedi Jackson, a spokeswoman for the San Diego Water Department. "We didn't know about it until it blew."  The hole, about 8 feet deep and 30 feet in diameter, rendered the alley impassable. The family that owns the boat and SUV, the Purbaughs, had been on a vacation to Mexico and returned just hours before the pipe burst.  Anthony Purbaugh, a medical-supply salesman, didn't want to talk to the media, but friends said he used the boat for fishing and surfing.  "The car can be fixed, but there's all sorts of special equipment on that boat," a Purbaugh friend, Tony Miklosovic, said as a city crew tried to hoist the SUV out of the sinkhole using two tow trucks and cables.

The faulty pipe was made of asbestos and concrete, which doesn't corrode. Breaks in that type of pipe can be caused by a soil shift or massive fluctuation in water pressure.  The city recently finished upgrading a nearby sewer line, and Jackson said investigators will also look into whether that project had any effect on the water main.  City crews were trying to fill the sinkhole last night, but Jackson said she wasn't sure how long it would take to patch it. The Purbaughs and anybody else whose property was damaged can file a claim with the city, Jackson said.

Alex Roth: (619) 542-4558; alex.roth@uniontrib.com

The Water Department's Tedi Jackson photographed the sinkhole, the SUV and the boat.

SEAN M. HAFFEY / Union-Tribune.  A massive break in a water main created a sinkhole in a Point Loma alleyway that swallowed this Chevy Tahoe and 22-foot-long boat. Even a backhoe sent to help clean up yesterday fell into the hole, which was about 8 feet deep and 30 feet in diameter.

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