LYNN – An lightning-laden thunderstorm that hit the North Shore Saturday evening proved to be a lingering nuisance as area businesses, residents, motorists and fire departments felt the effects of flooding and power outages hours after the rains had passed.?At about 6:30 last night we had what appears to be an apparent lightning strike on one of the transmission lines that services the North Shore,” said National Grid spokesman David Graves. “We initially lost service to about 25,000 customers.”An additional 29,000 customers, including some in Lynn, Saugus, Nahant, Revere and parts of Swampscott, lost power after the company was forced to cut power due to an overload. National Grid restored power to the second group at about 7:25 p.m., Graves said, but about 4,000 customers were without power until as late as 5 a.m. Sunday.Graves said the widespread outage was out of the ordinary for the company, even during a thunderstorm.?At the peak of the outage, 54,000 customers on the North Shore were without power,” Graves said. “It was a very large outage.”Once the lights went out, area fire departments became “inundated” with alarm calls, that vast majority of which turned out to be a result of the outages.?We were out all night with the power outages in a couple different areas for several hours,” Saugus Fire Chief Jim Blanchard said. “It usually trips the alarms so there were lots of fire alarms coming in and you have to take them all seriously because you don?t know that they?re all related to the power.”Saugus firefighters also rescued four people trapped in elevators around the town.?Any place that has an elevator there seemed to be a person stuck in it,” Blanchard said.While the fire department remained busy long after most of the power had returned, there were no reports of downed trees, motor vehicle accidents or fires in Saugus, Blanchard said.Lynn District Fire Chief Jack Barry said the department had its hands full during and after the storm, but no injuries or heavy damage had been reported.?There were a lot of alarm systems being set off and we did do some running around at the peak of the storm but nothing of any severity,” he said.Many of the businesses along the commercial stretch of Route 1 in Saugus were impacted financially by the outage. Bob Wong, whose father owns Kowloon Chinese Restaurant on Route 1, said the building lost power around 6:30 p.m., a peak period for the business, and the backup generators failed, forcing the restaurant to close for over four hours.?Normally we have a smooth transition with three generators that take care of the entire restaurant, but two generators went out for whatever reason,” Wong said. “We closed until it came on again at about 11 p.m. and almost filled the restaurant up, but at that point it was too little too late.”Motorists traveling southbound on Route 1 Saturday evening had headaches of their own as flooding shut down the Lynnfield Tunnel just after 6 p.m., further backing up already heavy traffic, Blanchard said.Two feet of water stood over Essex Street in Peabody from Margin to Sheldon streets as of 6:04 p.m., according to the National Weather Service.Taylor Provost can be reached at [email protected].