The Kmart store in Iwilei is expected to open at 7 a.m. as normal this morning after the accidental opening of its sprinkler system shut it down for most of Thursday.

Firefighters responded to the alarm call about 11:10 a.m. but found neither smoke nor fire, said Capt. Terry Seelig, Honolulu Fire Department spokesman.

There were no injuries, and water and ceiling panels fell from the ceiling onto an empty area so there was minimal damage to contents, Seelig said.

But water spread throughout the store and firefighters spent the next 3.5 hours doing mop-up, he said.

Firefighters gave store managers the OK to reopen provided the sprinkler system could be restored to operating order.

A store manager said officials are assessing the damage and expected to have the store open by this morning.