In an effort to improve communication among first-responders during fires, earthquakes and other disasters, Los Angeles area officials Monday announced the receipt of a $155 million federal grant to develop a regional radio system.

The system, which will take three to five years to develop and cost $700 million, will allow public safety officials to communicate on the same channels and radio frequencies.

"In the fires we've had over the last several years in Malibu, Calabasas and Topanga, we had Ventura County firefighters who can't communicate with Los Angeles County sheriffs. We had county firefighters who can't communicate with law enforcement agencies that come to assist us from other jurisdictions," county Supervisor Zev Yaroslavsky said at a news conference.

South Bay Rep. Jane Harman, who has been working on the issue for years, said the federal money was the largest single grant ever for a regional emergency communications network.

"It is welcome news for the residents of Los Angeles County, the largest county in America, which has seen its share of wild fires, earthquakes and riots and has the potential to see tsunamis and major terrorist attacks," Harman said.

Sheriff Lee Baca said the county and other agencies already have set aside $140 million for the project.

"There will be 1,000 frequencies and 500 channels that will be operating when this is done," Baca said. "This is unprecedented throughout the entire United States. It will be indeed the finest communication system in the world."

Known as the Los Angeles Regional Interoperable Communications System, the integrated wireless voice and data communications system will support more than 34,000 first-responders in the region, including neighboring counties.

Among other things, the network will enable computer-aided dispatch, rapid law enforcement queries, real-time video streaming, patient tracking and geographic information services for first-responders.

Formerly launched in 2009, the project has been in the works for years and was inspired by the Sept. 11, 2001, terrorist attacks.

"No one will forget that many first-responders died on 9-11 because two NYPD helicopters circling overhead could not warn firefighters climbing up the World Trade Center towers that the towers were glowing red and immediate evacuation was required," Harman said.

Locally, Harman said there have been numerous instances in which firefighters had to swap radios or rely on runners and drivers to relay messages during emergencies.