Three men injured after scaffolding on house collapses, send all three crashing to the street below in San Francisco, California

Three workers were hurt Friday, with two suffering life-threatening injuries, when they plunged from makeshift scaffolding at a construction project near San Francisco's Twin Peaks that city officials said lacked permits and violated a number of safety codes. The building's owner has a history of flouting permit procedures and employing unsafe practices, according to the city's Department of Building Inspection. The three men were working on the roof of a home at 1412 Clayton St. about 9:30 a.m. when half of the scaffolding - a wooden platform nailed into the side of the house - broke, sending them 25 feet onto the concrete below, authorities said. "I was working in the garden and I heard a crash, a really bad crash," said neighbor Chris Smith, 66. "They were lying on the concrete. They didn't look like they could move." A Fire Department spokeswoman, said the men - ages 24, 50 and 58 - were taken to San Francisco General Hospital with broken bones and internal injuries. The building's owner, had no work permits on file with the city, nor does he have permits for renovations going on at the house he owns next door at 1406 Clayton St., said a spokesman for the Department of Building Inspection. The lack of permits for the next-door location is especially troubling, the spokesman said, because workers were removing tiles that contained asbestos - and needed a hazardous material permit and specific training to do so. Two stacks of those tiles sat on a low ledge off the sidewalk Friday, and police officers worked to keep reporters and passersby away from them. "It looks like this is a property owner that doesn't believe in following state law or the permit code system here," a spokesman said. "That will obviously need to change." The owner, who was at the scene Friday speaking to police and inspectors, declined to be interviewed. City records show inspectors issued the owner a substandard building notice for 1412 Clayton St. - the one with the collapsed scaffolding - in 2000, ruling that the house was uninhabitable. Still, neighbors said, the owner allowed his workers to live there. Cal/OSHA, the state's workplace safety regulator, is conducting an investigation into the workers' injuries. While the probe could take up to six months, an associate safety engineer said after he arrived at the home Friday that the job clearly violated a number of safety rules. For instance, the makeshift platform required a railing, he said. He was especially concerned with a mechanical lift whose extendable platform hung precariously close to the roof and the faulty scaffolding.