Phone records obtained by the National Transportation Safety Board show that train engineer Robert Sanchez, who was operating a Metrolink commuter train in June when it collided head on with a Union Pacific train, had been texting on his cell phone just seconds before the crash. The crash killed 25 people.

Records show that Sanchez, who was himself killed in the crash, had sent his last text message at 4:22:01 pm, and the crash occurred 22 seconds later at 4:22:23. A minute before that, at 4:21:03, he had received a text message from someone yet unidentified. On September 15, investigative officials subpoenaed Verizon Wireless, Sanchez’ cell phone carrier for the last 30 days of his cell phone records.

Meanwhile, another lead is investigated as a few teenagers, rail enthusiasts, said that they had been exchanging messages with Sanchez just before the crash. The teenagers’ families provided investigators with their cell phone records. Mr. Sanchez’ phone has not yet been found despite a month of continuous combing through the crash site.

Robert Sanchez, who was 46, had been working two shifts that day. During the first – 6:44 am to 8:53 am – he sent 24 text messages and received 21, and during the second – 3 pm to the time of the crash – he sent five and received seven.

Veolia Transportation, the Parisian agency which contracts engineers to Metrolink forbids them to have personal electronic devices near them during work, and also prohibits using cell phones on the jobs unless for emergency purposes.

Following the tragedy, and heavy political pressure to improve safety on trains, Metrolink is adding a second engineer to trains, and installing cameras in the cabs.

A bill was passed in Senate hours after these developments, which would require all major railroad and commuter lines to install GPS-based collision avoidance systems, including automatic braking, by December 31, 2015.