Indianapolis firefighters battled two house fires Wednesday morning on the northwest side. The first fire, which broke out in the 1100 block of West 35th Street about 3:30 a.m., caused an estimated $150,000 in damage. Two people escaped the residence unharmed. Less than an hour later, a vacant house less than a block away on 35th Street began burning. The blaze caused about $45,000 in damage. The fires are being investigated to see if they were set intentionally.