A look at recent deadly aviation accidents in the US

Three different models of aircraft have crashed in recent days in the U.S., killing 21 people in Missouri, California and Texas and leading to federal investigations into the causes

LAREDO, Texas -- Three different models of aircraft crashed in recent days in the U.S., killing 21 people in Missouri, California and Texas and leading to federal investigations into the causes.

One person died when a business jet crashed in Laredo, Texas, on Tuesday night. Eight died Monday when a B-52 crashed at Edwards Air Edwards Air Force Base in California. And 12 people were killed when a small plane full of skydivers went down Sunday in Butler, Missouri.

It's still too early to say what went wrong in the three accidents. The National Transportation Safety Board is investigating.

The twin jet, a Cessna Citation Latitude, was traveling from Los Cabos International Airport in Mexico to Austin, Texas, when it crashed on a highway not far from Laredo International Airport around 10 p.m. local time Tuesday.

Dashcam footage posted on social media shows the aircraft careening down the highway, taking out a light post before coming to a stop.

In a chaotic scene that some witnesses described as like being in a movie, people left their vehicles and frantically tried to free the six people inside as the plane was on fire. Two people ran to the aircraft with a sledgehammer and shovel, using them to strike the cockpit glass and try propping open the plane’s door.

With the jet tipped on its side and nearly sheared in half, several people managed to climb out it while a firefighter using a small ladder rescued the last remaining passenger who appeared to be unconscious. Police said a person on the plane died, while five officers were treated at a hospital for smoke inhalation.

The plane appeared to have experienced a mechanical failure, Laredo International Airport Director Gilberto Sanchez told KGNS-TV in Laredo. He did not provide details.

A Boeing B-52 Stratofortress crashed Monday while taking off at Edwards Air Force Base in California, bursting into flames on the runway and killing all eight people aboard.

The bomber was in the air a very short time before slamming into the ground about halfway down the runway. Officials at the base said it was taking part in a test mission as part of a program aimed at keeping the oldest aircraft in the U.S. fleet flying for decades to come.

Military personnel and government contractors were aboard the B-52 when it crashed. Aircraft manufacturer Boeing said two of its employees were among those killed.

Although it's too early to kn