It seemed like a big emergency. The Anchorage Fire Department sent nearly 20 firefighters to Cook Inlet and downtown Anchorage Tuesday morning for what 911 callers thought might be a sinking boat or plane crash.

There was smoke, all right. But no fire. Just a big misunderstanding and little communication -- at least at first -- between public safety agencies charged with protecting people on land and in the water.

The orange and white plumes rising from boats in the Inlet turned out to be the Coast Guard practicing shooting emergency flares. The agency just didn't tell the city what it was doing.

"It happened really quickly. They didn't know we were responding and we didn't know they were out there until we got there," said Battalion Chief Jim Vignola.

Firefighters were dispatched just after 10:30 a.m., after receiving calls reporting what looked to be trouble on the Inlet, Vignola said.

Anchorage police Lt. Dave Parker was in the District Attorney's office on K Street and grabbed a pair of binoculars to see orange smoke rising from a boat less than a mile from shore, he said. Then white smoke. Then a flare falling from the sky.

He checked with police dispatchers, who told him someone had called to report a boat in distress.

"They thought it was a plane crash. They weren't sure because they were getting multiple reports," Parker said.

What police and firefighters didn't know at the time was that the smoke was simply the Coast Guard's maritime safety and security team training to use flares, some that fire into the air like bottle rockets and parachute to the ground.

About 25 people were training on two 25-foot boats, said Petty Officer 1st Class David Mosley. An area where the Coast Guard usually trains on Fort Richardson was unavailable, he said.

Before the exercise, the Coast Guard told the Alaska Rescue Coordination Center at Elmendorf Air Force Base and Coast Guard district command in Juneau of the training and alerted boats in the area over VHF radio. The agency's protocol didn't call for telling local police or fire officials, Mosley said.

All told, the department sent nine vehicles including an engine, a truck company, medics and divers to downtown and the Ship Creek boat launch Vignola said.

"Without knowing exactly what it was, we went loaded for bear, so to speak. Loaded just in case of the worst-case scenario," Vignola said.

When firefighters arrived, they spotted a Coast Guard boat that was putting up flares but didn't look to be in distress. Vignola made a call, learned of the training and canceled the rescue.

Coast Guard officials said "they will be sure to notify AFD and APD dispatch directly of any training events in the future," he said.

As a precaution, fire officials would have responded in the same way even if they knew the Coast Guard training was happening in the area, he said.

"It's just be like responding to an automatic fire alarm in a residential unit. Nine times out of 10 it's unattended cooking or burnt popcorn or burnt toast," Vignola said. Still the firefighters go, just in case.

Vignola said he didn't now what the cost of city's response might be.

The Coast Guard is working with the city to make sure the mix-up isn't repeated, Mosley said. "The lack of communication between ourselves and the fire department will be looked at and learned from."

After firefighters arrived, the flare training was canceled for the rest of the day.