Flooding was reported at both the Westfield Southcenter Mall and the Bellevue Square Mall.
Heavy rain overwhelmed the rooftop drainage system at the Southcenter Mall, sending torrents of water into the mall's atrium and several of its stores, according to Marty Grisham with the Tukwila Fire Department.
The puddled water on the roof has fully drained and Grisham said he does not believe the leak weakened the structure of the mall.
"The thing it indicates to us is that we had a major, major storm come through," Grisham said. "I have a call into the National Weather Service. I'm anxious to hear what kind of system came through here because it was a storm beyond what we've seen. It was thunder and lightning of course, and just a torrential downpour."
Ennis Dempsey had just left a movie when he noticed the flooding.
"We were watching movies and tried to come down and security wouldn't let us and I noticed a bunch of water in the entranceway there," he said.
The rain also caused flooding in at least two separate sections of the Bellevue Square Mall, according to Lt. Troy Donlin with the Bellevue Fire Department.
Fire crews first responded to reports of flooding just after 8:30 p.m. near the mall's eastern entrance and in the northwest corner of the structure.
Donlin isn't sure exactly where the water got into the mall, but he said as many as 10 stores were damaged.
Shoppers inside the mall said they were shocked at how much water had poured in.
"In the Apple (store) there was like a waterfall in the back of the store," said Natasha Carroll. "I saw probably 40 people gathered outside the store and they had everybody who doesn't work there outside."
The Seattle Public Utilities "Rainwatch" website estimates there was between 0.20 and 0.50 inches of rain in the hour before the flooding in Bellevue and Tukwila.