When tornadoes broke out across Minnesota last month, many people around the state heard sirens sounding in their communities and headed for shelter.
But not Jean Buckingham.
The Rochester retiree said she didn't know anything about the storm in her city until it was in her yard.
"All of the sudden, I though the window was going to go in on me," Buckingham said. "I ran back into the master bedroom and it sounded like someone was throwing stones on that window."
What she didn't hear was the air siren that Olmsted County installed nearby -- because it didn't go off.
A PATCHWORK SYSTEM
That's not uncommon. Across Minnesota, no one knows where all the sirens are, how far they can be heard, or even how many of them there are.
There is no state law or state agency that monitors weather sirens, whether they're activated or even if they're kept in working order. The systems belong to a patchwork of counties and cities -- and some of the sirens are even privately owned.
"All 87 counties in Minnesota kind of do things differently," said Doug Neville, a spokesman for the Minnesota Department of Public Safety. "They set their own policies on how the sirens work, when they sound the sirens."
In the case of the Rochester siren, Olmsted County authorities blame a software glitch. The National Weather Service had issued a severe thunderstorm warning, and was transmitting the alert over its radio network.
A SURPRISE FOR SOME
But no one heard the siren in Buckingham's neighborhood.
"No, we didn't. That was terrible, not to have a warning," Buckingham said. "But I was watching it and according to the clouds, it was not supposed to hit Rochester. But it did."
Buckingham said if she had heard the siren, she might have sought shelter in a nearby church or elsewhere, since her townhome doesn't have a basement.
Luckily, she wasn't hurt. The tornado tore some shingles off her roof and damaged her garage. Some of her neighbors weren't as lucky -- a handful of the townhomes in her development were destroyed.
No one was reported to have been injured.
Red Wing had a similar experience earlier this month. Eighteen of the city's 26 warning sirens were silent as a severe thunderstorm swept through the area.
Again, no injuries were reported, and the damage was much less serious in Red Wing.
But if residents weren't watching the skies, listening to the radio or watching TV, the rough weather came as a surprise.
LIGHTNING BLAMED FOR OUTAGE
Authorities still don't know for sure what caused that siren outage. The sirens worked before and after the storm, said Diane Richter-Biwer, director of emergency management for Goodhue County, which operates the system.
"The technicians worked on it for a couple of different days, and they had determined it was probably lightning that had struck at the time that they were transmitting the signal, from dispatch to the radio tower, to activate the sirens," she said. "So it interfered with some of the signals going out. It was the only thing they could figure out."
State officials don't know how often a siren doesn't sound.
The only time the state gets involved in any siren issues is within 10 miles of the two nuclear facilities in the state -- the Monticello plant, and the Minnesota side of the Prairie Island facility, Neville said.
However, some counties and cities are very meticulous about their sirens.
Ramsey, Anoka and Hennepin counties all contract with a Blaine company that tests the sirens electronically, on an almost daily basis.
Company officials said they review the data on a real-time basis and regularly send the results to city and county officials.
NOT USEFUL IN RURAL COUNTY
At the other extreme, though, some places do not even bother with sirens. Grand Marais used to have the only sirens in Cook County -- much of which is the Superior National Forest.
But officials shut them off so long ago that Cook County emergency manager Jim Wiinanen can't remember when they worked.
"As near as we can figure out, some time before the mid-'90s, the civil defense sirens were in place and were tested once a week," he said.
Since then, they haven't been.
Wiinanen said there have been only about two tornadoes in the county since World War II, and the sirens seemed more bother than they were worth. He said it cost too much to maintain them and some residents complained about the noise. He doesn't know if anybody bothered to take them all down.
Cook County is looking at implementing a "reverse 911 system" instead, that would call residents on the phone to warn them if they need to take shelter.
Editor's note: The original version of this story stated incorrectly that a tornado warning was issued for Olmsted County on June 17. It was a severe thunderstorm warning. The current version is correct.