DENVER -- A portion of South Lowell Boulevard collapsed after a water main broke Tuesday morning, Denver Water said.
The 12-inch main broke about 6 a.m. at Lowell and West Greenwood Place in southwest Denver.
Officials were on the road when the sinkhole formed. There were no injuries.
Water was shut off to five houses and traffic was detoured. Southbound Lowell was closed between West Floyd Avenue and West Greenwood Place.
It's not known how long the repairs will take, but pipe and road repairs, and cleanup efforts will last all day.
Denver Water said similar breaks are usually caused by temperature fluctuations. The age and material of the pipe, soil type, corrosion and water flow also can contribute to breaks.