Twinsburg Township -- The sight of flames peeking out from thick, black smoke Sept. 25 just before 12:30 p.m. got the attention of 911 callers from as far away as Stow and Geauga County.

The first call to dispatch to report the flames and smoke on the grounds of Regency Technologies, 1831 Highland Road, came from a resident on Glenwood Drive, more than 4 miles away.

Twinsburg firefighters, aided by Hudson, Macedonia and Oakwood departments, arrived at 12:33 p.m. to fight fires in three semi trailers, said Twinsburg Fire Department Capt. Steve Bosso.

The trailers were tightly packed to the brim with old computers and other electronic recyclables, Bosso said.

"Everything from boom boxes to cordless phones and DVD and VCR players," Bosso said.

Before they could extinguish the flames, firefighters waited for company employees to arrive to tip the trailers on their sides, Bosso said.

"They had to tip over the trailers so we could get to the fire," Bosso said. "Once they were tipped over, it went pretty rapidly."

The air was heavy with the smell of burning plastic, causing firefighters to wear air tanks, Bosso said.

"It was a challenge, but the guys worked hard," Bosso said. "We used thermal imaging at the end to make sure there weren't any more hot spots."

Firefighters cleared the scene just before 4 p.m., Bosso said.

No one was injured, he said. Deputies controlling traffic flow were evaluated, since they were breathing in the heavy smoke. They refused further treatment, Bosso said.

The trailers were a total loss, he said.

"Everything on the bottom was melded together," Bosso said.

He said the fire likely started in the middle trailer, spreading to the trailer on either side. As to the cause, Bosso is confident he knows the answer, but lost any tangible evidence as to the starting point when the trailers were tipped.

"It was probably heat from a battery source that could have smoldered for days," he said. "It wasn't suspicious in any way."

Metal may have fallen against a battery from one of the discarded devices, causing heat, Bosso said.

"It was a perfect storm with the batteries against some metal, able to heat up slowly," Bosso said. "With all the plastic, you've got a fire going."

A call to the company seeking comments was not returned.