On April 17, SWR17K was cleared for takeoff on KJFK's runway 4L and had accelerated to about 40Kts when the flight crew rejected the takeoff because of traffic on the runway. Several aircraft had previously landed on the parallel runway 4R and were given clearance to cross runway 4L. The flight crew of SWR17K spotted the crossing traffic and stopped their takeoff roll. They exited runway 4L at the crossing runway 31L and taxied back to the departure end of runway 4L and took off about 15 minutes later. At the time, runway 4L was being handled by tower frequency 123.9 and 4R was handled by tower frequency 119.1
