The Wells Fargo History Museum in downtown San Francisco was robbed of gold nuggets early Tuesday, police said. Three people wearing ski masks reportedly drove an SUV through the front windows of the museum at 420 Montgomery St. about 2:30 a.m. One person then held the security guard at gunpoint while the others took gold nuggets from a display case, according to police. The trio fled in a four-door sedan, police said, and no arrests were reported as of 8:40 a.m. Tuesday. Neither police nor Wells Fargo have provided the dollar value of the gold nuggets taken. Police later determined that the SUV was stolen. NBC Bay Area reported that a dark-colored Chevy Suburban remained in the building until it was towed away at 7 a.m.A Wells Fargo spokesman said the company is grateful no employees were injured during the robbery. Spokesman Ruben Pulido also said the company is grateful that the museum's historic stagecoaches went undamaged. Officials with Wells Fargo said they are cooperating with the investigation. Pulido said the museum will reopen so it can serve the thousands of people who visit each year. The museum is at the site where Wells Fargo opened for business in 1852.