So What Came . . . ?

The RAIN . . . pouring into the basement, pouring into buckets quickly placed under the "turned on faucet wall"
an evacuation took place . . .
and the next moring, look how the buckets were bulging . . .
This was the culprit . . . a backed up city drainage channel that poured through this opening, over the sidewalk and down the hill, into the front yard, and down into the basement.