On September 11, 2001, UAL175 nearly collided with 3 planes on its way to the World Trade Center, AAL11, DAL2315, and MEP7.
United 175 was a Boeing 767 that had 51 passengers, and 9 crew, not including the 5 hijackers aboard.
Midex 7 was a McDonnell-Douglas DC-9 that had 30 passengers and 5 crew aboard.
In this scenario, at 9:01 AM, near the border between New Jersey and Manhattan, UAL175 and MEP7 start to meet in the same spot.
The ATC conversation went like this, prior to the incident.
LGA ATC:
Midex 7, Midex 7, are you with me?
MEP7:
Midex 7 is with you out of 7 for 4,000.
(At this point, the controller then realizes that MEP7 and UAL175 are on a collision course)
LGA ATC:
Roger, Midex 7, turn left now! Head two-four-zero degrees now, as quick as you can!
(MEP7 then turns left, and this is the last few seconds of conversation the ATC has with MEP7)
MEP7's right wing hits UAL175's right wing, causing an explosion. Due to the amount of fuel in both planes, the fire expands quickly. But, due to the size of the DC-9, MEP7's fire spreads faster, and it disintegrates over the East River near Riker's Island.
UAL175, with 1 wing missing, and a spreading fire, begins to bank to the right, and crashes near a wastewater treatment plant in Hunts Point, New York, killing approximately 20-50 people on the ground.
The death toll was about 120-150.
Is this plausible?