An estimated several hundred gallons of gasoline spilled Sunday into the Alhambra wash and was moving south toward San Marino.
Los Angeles County Hazmat and Los Angeles County Flood Control crews were at the scene as of around 8 p.m. Sunday, South Pasadena police said.
Pasadena and Los Angeles County Hazmat units arrived at the scene to handle the cleanup, she said. L.A. County Public Works crews will handle flood maintenance outside the city limits, according to the South Pasadena police.
Alhambra police said the spill left a lingering gas smell, which was expected to dissipate sometime late Sunday night or early Monday morning.
There was also an earlier gasoline spill in Pasadena that happened when a vehicle crashed into a gasoline pump at a Union 76 station, releasing an estimated 1,300 gallons of gasoline.
The crash happened around 3:15 p.m. at the corner of Glenarm Street and Arroyo Seco Parkway, according to Pasadena spokeswoman Lisa Derderian.
The spill was caused after the emergency shutoff on the pumps malfunctioned, Derderian said.
Residents near the spill sites were advised to stay inside their residences with the windows and doors closed.