A fire in North Hollywood that lasted under thirty minutes last night ended with four minor injuries, two of which with firefighters. At 11:17 p.m., the Los Angeles Fire Department was called to a single family home on Whitsett Ave. near Roscoe Blvd. It took 35 firefighters 22 minutes before a knockdown was called and in the midst of all that, two firefighters sustained minor injuries when a patio fell on top of them. Two other civilians, both an elderly male and female, were treated for smoke inhalation. The cause of the fire is undetermined.