Anchorage firefighters are responding to a fire at a South Anchorage apartment building Friday afternoon.

AFD dispatchers say 13 units were sent to the 3700 block of Casper Court, in response to a call just before 1:40 p.m.

Initial reports indicate that a resident of an upstairs unit saw a mattress which had been set on fire.

Channel 2 has a crew en route.

This is a developing story. Please check and the Channel 2 newscasts for updates.