An early-morning fire Friday that damaged a Lawrence house and injured one resident was caused by improperly discarded smoking material, fire investigators determined.

A still-burning cigarette or some other smoking material was left on a bed and set the coverings on fire, Fire Marshal Rich Barr said. Damage to the house at 1322 Mass., which is occupied by three men, was estimated at $30,000, he said. Most of the damage was confined to the second floor.

Lawrence Firefighter's worked a early morning fire around 7:15 a.m. Friday morning in the second story of a older home at 1322 Massachusetts, caused heavy smoke and some water damage to the structure. This firefighter uses a device that looks for hot spots where fire might be hiding behind walls.

One man was taken to Lawrence Memorial Hospital by ambulance, but his condition was unavailable. His name wasn’t being released because of federal medical information rules, Barr said. He did say the injuries were not thought to be life-threatening. The injuries were caused by burns and smoke inhalation, Barr said.

• 6News video:Fire breaks out in central Lawrence

Lawrence-Douglas County Fire & Medical responded to the fire, above, at 7:18 a.m. The 1300 block of Massachusetts Street was barricaded to traffic until about 9:15 a.m.

The Douglas County chapter of the American Red Cross is assisting the victims.