A fire that struck a two-story self-storage building in Sylmar damaged seven units before being contained by 110 firefighters with no injuries reported, authorities said. The incident was reported at 10:17 a.m. Friday on the 13000 block of Foothill Boulevard, where two units on the first floor were on fire, said officials from the Los Angeles Fire Department. "It's very hot, very smoky - and there are probably a lot of stored materials in these units that they have to pull out for final extinguishment," said David Ortiz of the Los Angeles Fire Department before the knockdown. "It's taking a lot of manpower to do that. There's no active flames that can be seen." Fire officials called the inferno a "major emergency" in an alert message. Ortiz said the firefighters were from 17 different fire companies, and no injuries were immediately reported. The fire was knocked down at noon - an hour and 34 minutes after it was discovered, fire officials added. Wind was a factor in the delayed knockdown time, officials explained, but what made the incident difficult was the first-floor fire burning the floor above, making it difficult to access the second floor. Los Angeles Fire Department spokesman Brian Humphrey said the cause of the fire was under investigation and added that firefighters would be at the location for hours to "dig through the piles of debris" to make sure there are no hidden fires. They would also separate the storage items so they could be tracked back to the unit of their origin. "As you know, people typically purchase these units by the square foot and pack them by the cubic foot," Humphrey said.