By Peter Szekely

July 3 (Reuters) - The parents of one of the 58 people slain in a 2017 Las Vegas mass shooting sued the makers and sellers of the assault-style rifles used in the attack, saying they knew the weapons could be jury-rigged to work similarly to illegal machine guns.

The wrongful death lawsuit placed blame for the high death toll in the deadliest mass shooting in modern U.S. history squarely on the manufacturers and dealers who allegedly knew the weapons could be converted into rapid-firing machines.

The lawsuit filed by James and Ann-Marie Parsons, whose daughter Carrie was struck by one of the 1,049 shots fired in the 10-minute Oct. 1, 2017, barrage on 20,000 unsuspecting concertgoers, seeks unspecified damages from 16 gunmakers and gun dealers.

"The events of Oct. 1 would not have occurred but for the defendants' illegal and wrongful conduct," said the complaint, which was filed in Nevada state court in Las Vegas.

The gunman, Steven Paddock, brought ammunition and an arsenal of 12 semi-automatic AR-15-style rifles that he converted with "bump stocks" to fire about as quickly as fully automatic weapons. He ended his attack by taking his own life.

Bump stocks use a gun's recoil to bump its trigger, enabling a legal semi-automatic weapon to fire hundreds of rounds per minute as if it were a fully automatic machine gun. Machine guns are illegal in the United States.

The incident prompted the Trump administration to implement a ban on bump stocks on March 26, which the Supreme Court upheld in at least three challenges.

The lawsuit alleges that the defendants knew the ease with which AR-15s could be made to fire similarly to illegal machine guns, not only with bump stocks, but with household items such as shoe laces and rubber bands, and promoted them that way.

The lawsuit said "AR-15s were the weapon of choice for mass shooters looking to inflict maximum casualties," at targets including Sandy Hook Elementary School in Connecticut, an Aurora, Colorado, movie theater and an Orlando, Florida, nightclub.

"It was only a question of when - not if - a gunman would take advantage of the ease of modifying AR-15s to fire automatically in order to substantially increase the body count during a mass shooting," the lawsuit said.

The lawsuit names as defendants Colt Defense LLC and its Colt Manufacturing Co LLC subsidiary; Daniel Defense Inc; Patriot Ordinance Factory; Herstal Group and its FN America and FN Herstal subsidiaries; Noveske Rifleworks LLC, Christensen Arms, Lewis Machine & Tool Co, LWRC International LLC, Discount Firearms and AMMO LLC, DF&A Holdings LLC, Maverick Investments LP, Sportsman's Warehouse and Guns and Guitars Inc.

The companies could not be reached for immediate comment on Wednesday. (Reporting by Peter Szekely in New York; Editing by Scott Malone and Jonathan Oatis)