A water main break in Tustin left an apartment complex with significant damage and created a sinkhole Monday.
An urban search and rescue team was among the firefighters who responded to flooding from the break in a large water main.
The flow was shut down by the Irvine Ranch Water District within about an hour but left "significant damage" to the complex, Concialdi said.
A "large sinkhole" was created by the flood of water, he said.
Workers damaged the water main when they working at a vacant structure, authorities on scene said.