PITTSBURGH — The flash flooding that killed four people and forced others to swim to safety or climb onto car roofs was a freak accident caused by heavy rainfall that overwhelmed the sewer system as rush-hour traffic clogged low-lying city streets, officials said Saturday.
A mother and her two daughters, ages 8 and 12, died in Friday’s flood after they became trapped in their vehicle and rising water pinned it to a tree. Another woman’s body was washed into the Allegheny River, where she was found Saturday morning.
Back-to-back storms pounded the city with 3 to 4 inches of rain. The water drained onto Washington Boulevard, a main street near the Allegheny River on the city’s east side, with a force too great for a pair of sewer pipes 9 feet in diameter.
“There’s only so much any drainage system can handle,” said Jim Struzzi, a spokesman for the Pennsylvania Department of Transportation.
Rescue crews used boats to reach drivers marooned by floodwaters as deep as 9 feet. The Associated Press
