A pair of U.S. senators from New England are seeking answers from more than a dozen U.S. airlines in wake of a series of widespread flight cancellations and delays brought on by information technology systems issues.

Senators Edward J. Markey (D-Mass.) and Richard Blumenthal (D-Conn.) sent letters to 13 major airlines Tuesday, including American Airlines, Delta Air Lines, Southwest Airlines, United Airlines, JetBlue and Alaska Airlines, among others.

"We are concerned with recent reports indicating that airlines' IT systems may be susceptible to faltering because of the way they are designed and have been maintained," the senators wrote in the letter sent to the airline CEOs.

The letters come on the heels of a crippling computer outage that forced Delta to cancel thousands of flights last week. Last month, a router failure was blamed for hundreds of canceled Southwest flights.

"Some airlines use older technology, including software from the 1960s, as the backbone of their operations in 2016," added Markey and Blumenthal. "Not only may these IT systems be more prone to failure, but they may also be vulnerable to cyberattacks."