A Wall Street Journal report reveals that Malaysia Airlines Flight 370 sent a partial ping that could help investigators.

Investigators say that the final complete transmission was at 8:11 a.m., but there was a “partial ping” eight minutes later at 8:19 a.m. They say the plane likely hit the water between 8:19 and 9:15 a.m., when they did not receive the next scheduled ping.

Read more below, via the Wall Street Journal:

The final partial transmission from the missing Boeing Co. 777-200ER, which disappeared from civilian radar on March 8, "originates with the aircraft for reasons not understood," said Chris McLaughlin, senior vice president of Inmarsat PLC, which operates the satellite.

The company is investigating the partial ping—or digital handshake between the jet and the satellite—as "a failed login" to its satellite network or as a "potential attempt by the system [aboard the aircraft] to reset itself," Mr. McLaughlin said.

The cause of the partial ping could have several possible explanations, he added, but that human interaction with the satellite communications system had been ruled out.

"We're not looking at this [partial ping] as someone trying to turn on the system and communicate," he said.

Watch Trace Gallagher’s report above.

Read more on missing Malaysia Airlines Flight 370:

‘That Plane Went South’: Inmarsat Exec. Explains Data Used to Track Flight 370

‘Embarrassing, Irresponsible & Dishonest’: O’Reilly Slams Coverage of Missing Flight 370

Aviation Expert Remains Skeptical About Flight 370 Search Location