An improperly extinguished firework is believed to be the cause of a two-alarm fire early Wednesday morning in Renton. The call came in at about 1:30 a.m. for a home in the 15700 block of SE 168th St. According to fire officials, a firework was improperly disposed in a recycling bin in the back of a home there, causing it to reignite and spread to the house. The flames quickly spread to a second home next door. Everyone in both homes was evacuated safely, and nobody was hurt in the fire. Most of the damage occurred in the garages of the two homes.