TOLEDO, Ohio (AP) _ In a scene reminiscent of a 1950s horror movie, millions of mayflies smothered a power plant, reducing electricity for 290,000 homes and businesses and setting off hundreds of alarms throughout the city.

The equipment at the Toledo Edison plant was so full of bugs Sunday night that the mayflies began conducting electricity from one component to another, authorities said.

At that point, three of the four transformers shut down, and the voltage dropped for about 15 to 20 seconds. Lights dimmed, televisions shut off, alarms were triggered and hundreds of concerned residents called police.

``No one has ever seen a swarm like that at the plant. Mayflies have never shut down the facility like that,'' Edison spokesman Jim Proctor said.

The plant was back on line Monday after workers used hoses to wash away the mayflies.

The local mayfly population has increased in recent years because of measures to clean western Lake Erie. The peak time of year for mayflies is around the first week of July.

Residents in the Point Place section of Toledo have been shoveling mayflies off their sidewalks.

``This is disgusting,'' said Dave Kaseman as he looked at the side of his house, which was coated with mayflies. ``It makes your skin crawl.''

Mayflies were on the side of houses, utility poles. They were caked on store windows. The streets were covered with dead mayflies.

``Yuck,'' said Brian Fox, 11, as he tried unsuccessfully to sidestep dead mayflies on the street. ``This is gross.''