CHP officials said a backhoe operator struck a 6-inch diameter natural gas line near the Center Street on-ramp around 1 a.m.
Southbound and northbound lanes were closed for several hours while Southern California Gas Company crews worked to shut it off. The gas was finally shut off at 6:10 a.m.
Fire crews poured water on the leak to help dissipate the smell and help prevent any fires.
Traffic was rerouted around the site but heavy delays were reported.
The eastbound 91 Freeway connector to the northbound 215 Freeway was shortly closed, as well as the eastbound 60 Freeway connector to northbound 215 Freeway. Traffic was diverted off Iowa Avenue.
The northbound and southbound lanes have since reopened. The 215 Freeway Center Street on- and off-ramps were to remain closed for repairs until 5 p.m. Friday.
Officials said approximately 4,000 Southern California Gas customers in Riverside will be without natural gas service while repairs are underway. It is estimated that restoration will begin within 24 hours and continue over multiple days.
The reason restoring service is time consuming is because some people need to have their appliances and heaters restarted by gas company employees.
"We have to go back in and check on each location and make sure that it's safe, so we can relight their pilots," said Lea Petersen with Southern California Gas Company.
A command center has been set up by the Southern California Gas Company at 287 West La Cadena Drive in Riverside.