Corrections appended.

The Waltham Police Department shut down several streets last Tuesday after a major water main broke at the intersection of River and Seyon Streets, near Moody Street.

The break altered traffic patterns for morning commuters.

The Massachusetts Water Resource Authority — which operated the water main — reported that they had isolated the leak around 12:30 p.m. on Tuesday.

In a press release posted on its website, the MWRA stated, “The water main leak on River Street at Seyon Street in Waltham has been isolated. Water service to customers is not affected; however, traffic has been impacted.”

According to the City of Waltham, Pleasant Street and North Street were closed as crews repaired the main, and the City of Newton closed North Street. In the intersection where the water main break occurred, gallons of water could be seen flooding from under the pavement and forming pools in the street. Traffic impacts had ended by 9 p.m. on Tuesday night.

The MWRA was able to reroute water to restore service to customers, according to the Boston Globe.

The Globe also reported that contractors from the MWRA would be fixing the damage the leak caused, which included billowing, or outward swelling, of the concrete.

According to CBS Boston, a National Grid crew was also on the scene due to the possibility of a gas leak, though the Waltham Fire Chief stated that the gas odor could have been caused by some gas leaking from pipe joints when the water main burst. Gas leakage was previously a concern when a construction crew working on Moody Street struck and cracked a natural gas line in September.

—Abby Patkin

An earlier version of this article stated that the water main rupture caused water outages. A representative from the MWRA stated in an email to the Justice that the break did not cause any outages for customers. Additionally, the representative noted that traffic near the break was no longer impacted after 9 p.m. that evening. The article has been amended to reflect this information.