INDIANAPOLIS -- Many of Marion County's 2,000 firefighters say a new $4 million digital radio system could put them in jeopardy.

Fire chiefs lobbied for and were successful in delaying a planned switch to the new system, which had been set for next Tuesday, by one week, 6News' Jack Rinehart reported.

Firefighters contend that the new radio system isn't loud enough to overcome the sound of trucks, saws and other ambient noise and will compromise their ability to communicate.

"We're looking at the safety of our firefighters across Marion County," said Dale Henson, the Marion County fire chief's association president. "Hopefully … we can get the training done and get cut over to a system that we've spent a lot of money on."

Of direct concern is the combined oxygen pack and digital radio system, which some contend is vulnerable to poor environmental conditions and extraneous noise.

Fire safety advocates said problems with digital radios contributed to the recent deaths of three firefighters, including two in the Cincinnati area.

The deaths are under review for fire departments nationwide, including Indianapolis.

"It's truly a safety issue," said Mike Reeves, president of Local 416, the firefighter's union. "It's the No. 1 safety issue for our people. If we can't communicate, we've got to find another solution."

"We just want to make sure that it is the safest thing for our firefighters, so when they're protecting communities … that they're safe," Henson said.

Late Friday, the Marion County Emergency Communications Agency agreed to the delay.