City of San Diego crews worked through the night to repair a sinkhole closing a popular route in or out of Pacific Beach just north of Garnet Avenue. A 30-inch transmission water pipeline burst Monday, prompting the closure of the Interstate 5 off-ramp to Mission Bay Drive. The break, reported before noon, created a massive sinkhole estimated at more than 30 feet in diameter on the northbound lanes of Mission Bay Drive at Damon Avenue.