Some insurance premiums have risen as much as 200% and some insurance firms are refusing to provide coverage for businesses in the vicinity of the gas explosion that injured 24 people, destroyed a discount clothing store and caused closure of 150 Fairfax district shops last March, according to Los Angeles City Councilman John Ferraro. "I can understand . . . premiums going up to some extent," said Ferraro, "but I object to redlining or denying insurance to this area because of the explosion." Ferraro urged the underwriters to change their policies and warned that if no improvement is made, the council might try to influence the Legislature to take action in the matter. "If they can get away with stopping insurance here," he said, "this can spread, and that would be very dangerous."